Primary minerals of the Jachymov ore district

Roman Skala

Primary minerals of the Jachymov ore district

Roman Skala

2003, Journal of Geosciences

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Abstract

One hundred and seventeen primary mineral species are described and/or referenced. Approximately seventy primary minerals were known from the district before the present study. All known reliable data on the individual minerals from Jáchymov are presented. New and more complete X-ray powder diffraction data for argentopyrite, sternbergite, and an unusual (Co,Fe)-rammelsbergite are presented. The following chapters describe some unknown minerals, erroneously quoted minerals and imperfectly identified minerals. The present work increases the number of all identified, described and/or referenced minerals in the Jáchymov ore district to 384.

Figures (418)

Table 1. Chemical analyses of acanthite.

Fig. 1. J114P/C. Grow zone in sphalerite contains fine grains of acanthite. 1 — acanthite + sphalerite, 2 — sphalerite, 3 — rammelsbegite. Svornost shaft, 8" level, Geschieber vein. BSE image. Magnification 160x,

Table 2. Calculated unit-cell parameters of acanthite from Jachymov for the space group P2,/c.

Fig. 2. JO61P. 1 — aikinite, 2 — stannite, 3 — chalcopyrite. Giftkies adit. BSE image. Magnification 330x.

Table 3. Chemical analyses of aikinite. Table 4. Chemical analysis of albite.

Fig. 3. MP27/A-3. 1 — alloclasite, 2 — rammelsbergite, 3 — quartz. EliaS mine. BSE image. Magnification 400x. The mineral forms a thin rim on botryoidal rammelsbergite in the direction toward the surrounding quartz (Fig. 3).

Table 5. Chemical analyses of alloclasite. Table 6. Chemical analyses of anilite.

Table 7. Calculated unit-cell parameters of anilite from Jachymov for the space group Puma.

Table 10. Chemical analyses of annite. cleavage planes. It is associated with ferberite, topaz, apatite, scheelite and molybdenite. The sample comes from the Rovnost I shaft, probably from 8" level.

Even so, such crystals are in fact pseudomorphs of acanthite after argentite (Fig. 4).

Table 8. Homogenization temperature Th of fluid inclusions in ankerite.

Table 9. Calculated unit-cell parameters of ankerite for the space group R3. Argentite Ag,S

Table 11. Chemical analysis of antimony.

Fig. 4. Group of argentite crystals on carbonate gangue (width of figure 5 cm). Photo J. & E. Sejkora. Argentite occurs mainly in upper parts of Jachymov veins, where it forms veinlets together with other silver minerals and pyrite aggregates in carbonate gangue. Pol- ished sections show rare sections of crystals with com- bination of (100) and (111) faces, deposited on arsenides, mainly nickeline. The colour is silver white turning into grey after some time.

Fig. 5. JL16P/D-2. 1 — annabergite, 2 — pyrite, 3 — Ag-Fe-sulphides. Svornost shaft, 8 level, Geschieber vein. BSE image. Magnification 270x. Argentopyrite was decribed from Jachymov by Sarto- rius in 1866 [438]. Tschermak [469] considered the

Fig. 6. J166P (NM9527). 1 — argentopyrite, 2 — Ag-pyrite, 3 — ankerite. Svornost shaft, 8 level, Geschieber vein. BSE image. Magnification 20x.

Fig. 7a, b. NM4810. Cross-section of prismatic argentopyrite crystals as seen with single polarizer and crossed polarizers. Strong anisotropy indicates intergrowth of crystals in different orientation. Minor marca- site indicates beginning decomposition of argentopyrite. 1 — argento- pyrite, 2 — marcasite. Magnification 50x.

Fig. 8a, b. NM9527A. Anisotropic aggregate of argentopyrite as seen with single polarizer and crossed polarizers. Indication of cleavage at argentopyrite margin. Argentopyrite is extensively decomposed to acanthitet+marcasite aggregate. | — acanthite+marcasite after argentopyrite, 2 — argentopyrite, 3 — carbonate. Svornost shaft, 8" level, Geschieber vein. Magnification 50x.

Fig. 9. Hemispherical aggregate with argentopyrite crystals (width of figure 5 cm). Photo J. & E. Sejkora.

Fig. 12. J-853. Columnar crystals of argentopyrite on arsenic. Svornos' shaft. SE image. Magnification 330x. Photo A. GabaSova. Fig. 11. Group of argentopyrite crystals (width of figure 1.1 cm). Photc J. & E. Sejkora.

Fig. 10. Argentopyrite crystals on proustite (width of figure 9.5 mm). Photo J. & E. Sejkora.

Table 12. Chemical analyses of argentopyrite.

Fig. 13. Argentopyrite according to Schrauf in [492].

Fig. 14. Comparison of distorted six-member rings S-Fe-S—Fe—S—Ag in the structure of argentopyrite (top) and sternbergite [430] (bottom). Two Fe atoms are positioned above the triangle defined by S atoms and Ag atom is on the opposite side of the triangle.

Fig. 16. A projection of crystal structure of argentopyrite into a plane (100) shows deformation of 6 — member circles of S-Fe-S-Fe-S—Ag and their ordering in layers parallel with (010). Fig. 15. Pseudo-hexagonal motifs of 6 — member circles of S-Fe-S— Fe-S—Ag dominate in a projection of crystal structure of argentopy- rite into a plane (010).

Table 13. Calculated unit-cell parameters of argentopyrite from Jachymov for the space group P2,/c. lar intergrowth of argentopyrite and its alteration prod- ucts constitute irregular zones. Alteration proceeds from the centre of the crystal to the rims, and some marginal parts contain unaltered material.

Table 14. X-ray powder diffraction data for argentopyrite indexed in the space group P2,/c.

Table 15. Chemical analyses of argentotennantite.

Fig. 17. J160P/A. 1 — argentotennantite, 2 — rammelsbergite, 3 — pyrite, 4 — annabergite, 5 — quartz. Adit above Unruhe adit. BSE image. Magnification 800x.

Fig. 18. MP420A/D-3. 1 — fine-grained arsenic, 2 — coarse-grained arsenic, 3 — léllingite, 4 — galena, 5 — calcite. Barbora shaft. BSE image. Magnification 130x.

Fig. 19. VS4231. Botryoidal aggregates of arsenic on dolomitic carbonate. SE image. Magnification 100x. Photo A. GabaSova.

Fig. 21. Thin-bedded aggregate of arsenic (width of figure 8 cm). Photo J. & E. Sejkora.

Fig. 20. Aggregate of arsenic (width of figure 8 cm). Photo J. & E. Sejkora.

Table 17. Calculated unit-cell parameters of arsenopyrite from Jachymov for the space group P1.

Fig. 22. MP271B. 1 — arsenpolybasite, 2 — Hg-silver, 3 — calcite. Barbora shaft, 4"/5" level, No. 32 vein. BSE image. Magnification 800x. The mineral occurred in the central part of the Jachymov deposit. Its colour is steel grey with a greenish tint. Frac- ture is uneven, imperfect cleavage along the basal face for hexagonal orientation. Thin fragments are dark red in transmitted light. Granular aggregates up to 2 mm are enclosed in quartz-carbonate gangue. It also occurs in hexagonal tabular crystals or rare prisms.

Fig. 25. MP271E/B. | — arsenpolybasite, 2 — acanthite, 3 — rammels- bergite, 4 — perimorphs of rammelsbergite after silver, 5 — uraninite, 6 — calcite. Barbora shaft, 4/5" level, No. 32 vein. BSE image. Magnification 50x. Fig. 24. MP271B/A-9. 1 — acanthite, 2 — arsenpolybasite, 3 — rammelsbergite. Barbora shaft, 4'/5™ level, No. 32 vein. BSE image. Magnification 400x.

Fig. 23. MP271B/B-3. 1 — rammelsbergite, 2 — arsenpolybasite, 3 — uraninite, 4 — calcite. Barbora shaft, 4'"/5" level, No. 32 vein. BSE image. Magnification 270x.

Table 19. Calculated unit-cell parameters of arsenpolybasite from Jachymov for the space group C2/m. Table 20. Chemical analyses of arsenpolybasite.

This mineral was identified as a single elongated grain 80x10 um in size. It contains major W and Nb, signifi- cant Fe and low Ti, Mn, Ta, and Sn. The crystal is en- closed in annite with hematite positioned along cleav- age. The sample comes from the Rovnost I shaft, probably 8" level.

Fig. 26. MP271B/B-2. Tabular crystals of arsenpolybasite contain at margins mercurian silver accompanied by minor chalcopyrite. 1 — Hg-silver, 2 — arsenpolybasite, 3 — chalcopyrite, 4 — calcite. Barbora shaft, 4"/5" level, No. 32 vein. Reflected light, single polarizer. Magnification 260x. Arsenpolybasite is deposited on rammelsbergite and argentite in anhedral grains or thin tabular crystals. It is overgrown with chalcopyrite or other sulphides. It is en- closed in calcite or exceptionally dolomite. It shows char- acteristic dark red internal reflections along cleavage in a polished section (Fig. 26).

Fig. 27. Composition of arsenpolybasite from Jachymov compared with the solid solution in a synthetic system [441].

Table 21. Chemical analysis of aurostibite. a mixture with bismuth in a variable ratio. A small Au surplus may indicate the presence of minor free gold. The mineral is always enclosed in arsenopyrite or [éllingite. Aurostibite was identified in a single sample in associa- tion with gold, bismuth, unidentified Bi-telluride and clausthalite. The sample comes from the Barbora shaft, between 7" and 8" level, probably near vein 1S.

Fig. 28. J145P. 1 — ashanite, 2 — annite, 3 — hematite, 4 — quartz. Rovnost shaft, ore dump. BSE image. Magnification 530x.

Fig. 29. 1 — bismuth, 2 — aurostibite, 3 — l6llingite. Barbora shaft, T*/8® level, probably No. 1S vein. BSE image. Magnification 530. Aurostibite occurs in rounded grains of several microns in size. Pure aurostibite is exceptional — it usually forms

Fig. 30. Bismuth crystals in the gangue cavities (width of figure 1.3 cm). Photo J. & E. Sejkora.

Fig. 34. MP129. 1 — bismuth, 2 — léllingite. Rovnost I shaft, 10" level. Bergkittler vein. BSE image. Magnification 33x.

Fig. 32. MP94. 1 — bismuth, 2 — rammelsbergite. EliaS mine, 1‘ level, 2A vein. BSE image. Magnification 38x.

Fig. 33. MP97/A. 1 — bismuth, 2 — bismuthinite, 3 — rammelsbergite. EliaS mine, A vein. BSE image. Magnification 30x.

Fig. 36. JO24P. Skeletal aggregate of native bismuth is partly replaced by bismuthinite. Boundary between native bismuth and native arsenic is formed by a thin zone of rammelsbergite. Black areas are carbonate. 1 — arsenic, 2 — bismuth, 3 — bismuthinite, 4 — rammelsbergite, 5 — carbonate. Svornost shaft, 5" level. Reflected light, single polarizer. Magnification 130x.

Fig. 37. JO26P. Skeletal crystal aggregate of native bismuth is partly re- placed by bismuthinite. A rim of skutterudite protected bismuth against complete replacement. All ore minerals are enclosed in carbonate. 1 — bismuth, 2 — bismuthinite, 3 — skutterudite, 4 — carbonate. Svornost shaft, 5" level. Reflected light, single polarizer. Magnification 130x.

Fig. 35. MP329C. | — bismuth, 2 — safflorite, 3 — quartz. Bratrstvi shaft Adit level, Zdat Buh vein. BSE image. Magnification 80x.

Table 24. Calculated unit-cell parameters of bismuthinite from Jachymov for the space group Pbnm.

Table 25. Chemical analyses of bismuthinite.

Fig. 38. J121P. 1 — Sb-bismuthinite, 2 — bismuth, 3 — bismuthinite, 4 — rammelsbergite. Svornost shaft, 2"! level, Geschieber vein. BSE image. Magnification 1150x. Chemical composition is typically simple. Only one sample contained significant Sb. It was quartz gangue with skeletal bismuth rimmed by a narrow zone of rammels- bergite, which was covered by Sb-bismuthinite, confined to concave rims of rammelsbergite. Antimony content var- ied, with the maximum at Bi/Sb = 2 : 1. The specimen comes from the Svornost shaft, 2"? level, Geschieber vein.

Table 26. Calculated unit-cell parameters of bornite from Jachymov for the space group Pbca.

Fig. 39. MP421. 1 — bismuth, 2 — bismuthinite, 3 — calcite. Svornost shaft, 12" level, Bergkittler vein. BSE image. Magnification 6x.

Fig. 40. Hair-like bismuthinite crystals in gangue cavities (width of figure 1.3 cm). Photo J. & E. Sejkora.

Fig. 42. JO63P. Pressure fractures i in bornite < are filled by chalcopyrite. Zone with pyrite relics (high relief) contains tennantite. 1 — covellite, 2 — bornite. Rovnost I shaft, 3" level, Geister vein. BSE image. Magnification 230x. Fig. 41. JO14P. | — bornite, 2 — chalcopyrite, 3 — tennantite, 4 — pyrite. Svornost shaft, Adit level. Reflected light, single polarizer. Magnification 160x.

Table 27. Chemical analyses of bornite. examples of myrmekitic exsolved galena in bornite were observed. It may also form exsolutions in chalcopyrite. tite. However, in its total quantity in the veins, calcite is far behind dolomite.

* temperature of homogenization (Th) Table 29. Homogenization temperature Th of fluid inclusions in calcites from Jachymov.

isotropic temperature factors: Bca = 2.72(7) A?; Bc =2.7(1) A?; Bo = 3.579) A>. Table 28. Rietveld structure refinement of calcite from Jachymov. Calculated unit-cell parameters, unit-cell volume, fraction-coordinates of C and O, total temperature factor and parameters of the refinement accordance are included.

Table 30. Calculated unit-cell parameters of calcite from Jachymov for the space group R3c.

Fig. 43. SR99137/b. Irregular cassiterite grains enclosed by magnetite and flaky hematite. Cassiterite is in places replaced by sphalerite. In the matrix is also chlorite and quartz. 1 — cassiterite, 2 — magnetite, 3 — hematite, 4 — sphalerite, 5 — quartz. Skarn. Plavno. BSE image. Magnification 58x. According to Mrna and Pavlt, cassiterite is a common component in apical parts of younger granite, e.g., in the Rovnost I and Bratrstvi shafts. It forms grains up to 5 mm in size. Sometimes it penetrates the rocks of metamorphic exocontact in the form of thin and irregu- lar quartz veinlets. It is accompanied by arsenopyrite, less frequently wolframite in tabular crystals, and mi- nor chalcopyrite. Cassiterite does not occur in veins

Fig. 44. SR99139/a. Euhedral cassiterite enclosed in biotite mass in various stages of chloritization. 1 — cassiterite, 2 — biotite, 3 — chlo- rite. Skarn. Plavno. BSE image. Magnification 56x.

Fig. 46. MP 380. 1 — pyrite, 2 — chalcocite, 3 — bornite. Panorama mine, Zuzana vein. BSE image. Magnification 530x. Fig. 45. JO89P/F. 1 — chalcocite, 2 — bornite, 3 — quartz. Giftkies adit. BSE image. Magnification 400x.

Fig. 47. MP112*. Zoned chalcocite grains with up to 5 wt.% Fe in rims. Aggregate intergrowth of bismuth and bismuthinite in surroundings of chalcocite. 1 — chalcocite, 2 — Fe-chalcocite, 3 — bismuth and bismuth- inite. Rovnost I shaft. Reflected light, single polarizer. Magnification 60x.

Fig. 50. Chalcocite crystal drawing by Vrba [362]. Crystal forms: c(001), e(012), d(021), b(010), z(113), v(112), p(111), m(110), n(230), m(130), a(100). Fig. 49. Group of tabular crystals of chalcocite up to 2 mm (width of figure 5 mm). Photo J. & E. Sejkora.

Fig. 48. NM9087. Equant chalcocite crystal grown on native arsenic. SE image. Magnification 50x. Photo A. GabaSova.

Table 31. Calculated unit-cell parameters of chalcocite from Jachy- mov for the space group P2,/c.

Table 32. Chemical analyses of chalcocite.

Fig. 51. JO85P/D-5. 1 — chalcopyrite, 2 — Ag-chalcopyrite, 3 — freiberg- ite. No. | Adit. BSE image. Magnification 115x.

Table 33. Calculated unit-cell parameters of chalcopyrite from Jachymov. Table 34. Chemical analyses of chalcopyrite.

Number of atoms based on (O=14) or (O, OH =18) * HO calculated from crystallochemical formula

Fig. 52. MP190/E. 1 — galena, 2 — chalcopyrite, 3 — pyrite, 4 — calcite. 5 — dolomite. Svornost shaft. Daniel level, Anna vein. BSE image. Magnification 80x.

Table 36. Chemical analyses of clausthalite. enclosing gold and aurostibite, Bi-telluride and bismuth. The host rock is a dark, probably altered basic wall-rock from the Babora shaft, between 7" and 8" level, proba- bly near vein 1S. In the second occurrence, clausthalite with bornite and chalcocite is enclosed in milky white quartz from the Giftkies adit.

Table 37. Calculated unit-cell parameters of clinosafflorite from Jachymov for the space group P2,/n.

Fig. 53. MP271B/A-12. 1 — cinnabar, 2 — calcite, 3 — quartz, 4 — chlorite. Barbora shaft, 4"/5" level, No. 32 vein. BSE image. Magnification 680x.

Fig. 54. MP271D/G. | — cinnabar, 2 — calcite, 3 — rammelsbergite, 4 — mineralized wall-rock. Barbora shaft, 4/5" level, No. 32 vein. BSE image. Magnification 130x.

Table 38. Chemical analyses of clinosafflorite.

* The value estimated from unit-cell dimensions and thermal analysis. Theoretical value for USiOs, is 7.16 g.cm” [150]. Table 39. Calculated unit-cell parameters of coffinite from Jachy- mov for the space group /4,/amd and density.

Fig. 56. JI86P/1. 1 — coffinite, 2 — pyrite, 3 — chamosite, 4 — Fe-dolomite. Elia8 mine, AK vein. BSE image. Magnification 540x.

Fig. 58. MP390A/C. 1 — argentite, 2 — coffinite, 3 — uraninite. Rovnost I shaft, No. 13 vein. BSE image. Magnification 250x.

Fig. 57. MP271B/A-11. 1 — cinnabar, 2 — coffinite, 3 — pyrite, 4 — calcite. Barbora shaft, 4°°/5™ level, No. 32 vein. BSE image. Magnification 300x.

Table 40. Chemical analyses of coffinite.

Table 41. Calculated unit-cell parameters of covellite from Jachymov for the space group P6,mmce.

Fig. 59. Complicated texture of bornite enclosing silver and covellite. Fractures in bornite are filled by chalcopyrite and uraninite. 1 — silver, 2 —covellite, 3 — bornite, 4 — chalcopyrite, 5 — uraninite, 6 — roscoelite, 7 — quartz. Rovnost mine, 3" level. Reflected light, single polarizer. Magnification 160x.

Fig. 60. J138P/B. 1 — galena, 2 — covellite. Shaft No. 14. BSE image. Magnification 320x.

Table 42. Chemical analyses of covellite.

Table 44. Chemical analyses of diaphorite.

Table 43. Microhardness of diaphorite. Diaphorite forms anhedral to subhedral grains of micro- scopic size in microcrystalline intergrowth with pyrite and stephanite. These coatings cover massive stephan- ite covered by stephanite crystals. The specimen collect- ed in 1872 is in the Mineralogical collection, National Museum, Prague, No. NM9512 [333].

Fig. 61. J-928. Covellite crystals in cavity. SE image. Magnification 1100x. Photo A. GabaSova.

Table 45. Calculated unit-cell parameters of djurleite from Jachymov for the space group P2,/n. Table 46. Chemical analyses of djurleite.

Fig. 62. Dickite crystals. SE image. Magnification 690x. Photc Z. Mach [595].

Fig. 63. NM4798. Pseudohexagonal crystal of djurleite. SE image. Magnification 45x. Photo A. GabaSova.

Fig. 64. NM4798. Accessories on the surface of pseudohexagonal crystal of djurleite. SE image. Magnification 200x. Photo A. GabaSova.

Table 47. List of studied dolomite samples from Jachymov. Table 48. Homogenization temperature Th of fluid inclusions in dolomite from Jachymov. in proximity to the paramorphs, changing further away to pink colour.

Table 49. Rietveld structure refinement of carbonates from Jachymov. Calculated unit-cell parameters, unit-cell volume, fraction

Table 50. Calculated unit-cell parameters of dolo- mite from Jachymov for the space group R3. Table 51. Chemical analysis of dyscrasite.

Fig. 65. JIO5P/A-5. 1 — arsenic, free of corrosion, 2 — dyscrasite, 3 — corroded arsenic. Svornost shaft, Adit level, Hildebrand vein. BSE image. Magnification 720x. Dyscrasite was identified as round 5 Um grains enclosed in arsenic containing 7 wt.% Sb, set in dolomite gangue. Dyscrasite is limited to aggregates of arsenic, w gregates of arsenic free 30-40 Um wide outer zones or hich are deposited on larger ag- of Sb (< 0.5 wt.% Sb) and free of dyscrasite inclusions (Fig. 65). The sample comes from the Svornost shaft, Adit evel, Hildebrand vein.

Fig. 66. MP290C/H-6. 1 — bismuth, 2 — rammelsbergite, 3 — emplectite, 4 — calcite. Barbora shaft, 5" level, vein No. 32. BSE image. Magnification 660x. The mineral was identified as several acicular crystals to 0.5 mm long coated by an ultra-fine mixture of emplec- tite and pyrite surrounded by altered uraninite, and in- tergrown in porous brownish hornfelsic quartz. This sam- ple comes from the Schweizer vein. On another sample, emplectite occurs in short prismatic crystals up to 20 Um long deposited on rammelbergite aggregate, with a

Table 52. Chemical analyses of emplectite.

Table 54. Chemical analyses of fletcherite.

Table 53. Chemical analyses of ferberite.

Fig. 67. MP230/A-1. 1 — fletcherite, 2 — millerite, 3 — chalcopyrite, 4 — wittichenite. Eva shaft, 5"level, vein No.32. BSE image. Magnification 1000x. Fletcherite forms 5 Um wide zone along millerite—chal- copyrite boundary. It is associated with wittichenite.

Table 56. Homogenization temperature Th of fluid inclusions in fluorite from Jachymov.

Table 55. Calculated unit-cell parame- ters of fluorite from Jachymov for the space group Fm3m.

Table 57. Chemical analyses of freibergite. white) but fluorite of the carbonate-uraninite stage is violet turning to nearly black in proximity of uraninite lenses. In both cases, fluorite forms isolated grains, small aggregates or thin veinlets with euhedral crystals in vugs [351]. Galena PbS

Table 58. Calculated unit-cell parameters of galena from Jachymov for the space group Fm3m.

Fig. 68. G119C/D. 1 — freibergite, 2 — pyrargyrite, 3 — chalcopyrite. Svornost shaft, Geschieber vein. BSE image. Magnification 400x.

Table 59. Calculated unit-cell parameters of gersdorffite from Jachymov.

Fig. 69. J102P. 1 — galena, 2 — gersdorffite, 3 — quartz. Schénerz adit. BSE image. Magnification 16x.

Fig. 71. J102P. Gersdorffite rims formed after skutterudite are rimmed by rammelsbergite. The association shows newly formed gersdorffite, transport of S is documented by galena grains. | — As-gersdorffite, 2 — rammelsbergite, 3 — galena. Sch6nerz adit. Reflected light, single polarizer. Objective 20x.

Fig. 70. J115P. Arsenides have internal structure emphasized by strong corrosion and they are gradually altered to gersdorffite with variable S content. Radial or botryoidal sphalerite is deposited on arsenides. Chalcopyrite and matildite are rare. 1 — galena, 2 — nickel-skutterudite, 3 — As-gersdorffite, 4 — sphalerite, 5 — matildite, 6 — chalcopyrite. Rovnost II shaft, 6" level, vein perpendicular to the vein No. 16. Reflected light, single polarizer. Objective 20x.

Fig. 73. MP230/A. | — gersdorffite, 2 — galena, 3 — l6llingite. Eva shaft, 5 level, vein No. 32. BSE image. Magnification 1150x. Fig. 72. JL15P. Zone of crushed nickel-skutterudite, which is con- tinuously replaced by a mixture of rammelsbergite and gersdorffite. 1 — nickel-skutterudite, 2 — rammelsbergite + gersdorffite. Rovnost II shaft, 6" level, vein perpendicular to the vein No. 16. Reflected light, single polarizer. Objective 20x.

Fig. 74. J-723. Gersdorffite on nickeline. Svornost shaft, 10" level. SE image. Magnification 780x. Photo A. GabaSova.

Table 60. Chemical analyses of gersdorffite.

Table 61. Calculated unit-cell parameters of glaucodot from Jachymov for the space group Cmmm. Goethite FeO(OH)

Fig. 76. J-927. Radiating goethite crystals. SE image. Magnification 120x. Photo A. GabaSova.

Fig. 77. MP427/2. 1 — gold, 2 — bismuth and Bi-telluride, 3 — finely dispersed bismuth, 4 — léllingite, 5 — calcite. Barbora shaft, 7"/8" level. BSE image. Magnification 1000x. A single round gold grain of 3 1m in diameter con- taining low Ag was identified during the present study, on the boundary of /d/lingite and calcite grains and as- sociated with bismuth, aurostibite and an unidentified Bi- telluride. The last two minerals form mixture with bis-

Fig. 78. MP27/D-4. 1 — greenockite, 2 — siegenite, 3 — tennantite, 4 — quartz. EliaS mine. BSE image. Magnification 1200x. Another greenockite occurrence in grains up to 3 Um in sphalerite and 30 Um long grain in intergrowth with tennantite and wittichenite, in milky white quartz comes

Fig. 79. MP290C/H-4. | — sphalerite, 2 — greenockite, 3 — wittichenite, 4 — galena. Barbora shaft, 5“ level, vein No. 32. BSE image. Magnification 900x.

Table 63. Chemical analyses of htibnerite. Table 64. Chemical analyses of hyalophane.

Fig. 80. J112P. 1 — chalcopyrite, 2 — hyalophane, 3 — Ba-orthoclase, 4 — quartz. EliaS mine. BSE image. Magnification 400x.

number of atoms based on (O=8) Table 64. (continued)

Table 65. Chemical analyses of imiterite.

Fig. 81. MP271B/B-1. 1 — galena, 2 — imiterite, 3 — arsenpolybasite. Barbora shaft, 4"/5" level, vein No. 32. BSE image. Magnification 1200x.

Fig. 82. MP271D/F-1. 1 — imiterite, 2 — argentite, 3 — cinnabar. Barbora shaft, 4/5" level, vein No. 32. BSE image. Magnification 1000x.

Fig. 83. JO7IP. 1 — kaolinite, 2 — nickel-skutterudite. Svornost shaft, 12" level. BSE image. Magnification 200x.

Fig. 84. JO71P. 1 — nickel-skutterudite, 2 — nickel—-skutterudite with kaolinite. Svornost shaft, 12" level. BSE image. Magnification 16x.

Fig. 85. J185P. Wall-rock fragment replaced by kaolinite. 1 — bornite, 2 — kaolinite of variable orientation. Svornost, Daniel level, Trojicka vein. Reflected light, single polarizer. Objective 10x.

Number of atoms based on (O, OH = 9). * HO calculated from crystallochemical formula. Table 66. Chemical analyses of kaolinite.

Table 67. Chemical analyses of késterite.

Table 68. Calculated unit-cell parameters and density of krutovite from Jachymov.

Fig. 86. J126P/D. 1 — chalcopyrite, 2 — késterite, 3 — Sb-tennantite, 4 — stannite. Schénerz adit. BSE image. Magnification 360x. Késterite forms grains to 40 Um long separated from stannite, which occur in the same paragenesis. It is rare

Table 69. Chemical analyses of krutovite.

Fig. 87. J133P/2. 1 —krutovite, 2 - annabergite, 3} pyrite, 4 proustite. Svornost shaft, dump. BSE image. Magnification 230x.

Fig. 88. Greyish black spherical krutovite aggregates (width of figure 2 cm). Photo J. & E. Sejkora.

Fig. 89. JO74P/A-3. 1 — lautite, 2 — léllingite, 3 — bornite, 4 — galena, 5 — quartz. Svornost shaft, Daniel level, intersection of Trojicka vein with Geschieber vein. BSE image. Magnification 320x. A possibility remains that enargite replacing bismuth, reported by Ziikert [423] in a polished section, was also lautite, because of similarity in optical properties of enargite and lautite.

Fig. 90. MP150. Lindstrémite forms radiating lamellae penetrating along interfaces of chalcopyrite. Chalcopyrite aggregate contains pyrite with irregular replacement. Minor pyrite and marcasite rim lindstrémite. 1 — chalcopyrite, 2 — pyrite, 3 — lindstrémite, 4 — dolomite. Rovnost shaft, 6" level, Schweizer vein. Reflected light, single polarizer. Magnification 260x. Lindstromite in an intimate intergrowth with other sul- phides forms exsolutions in chalcopyrite (Fig. 90). Its white colour makes /indstrdémite distinct from other copper sul- phides and it has characteristic low polishing hardness. Size of aggregates does not exceed 20 um. Representative spot analyses by electron microprobe could be obtained only after careful work, due to irregular concave shape of grains and numerous inclusions. The studied sample comes from the Rovnost I shaft, 6" level, Schweizer East vein.

Table 71. Chemical analyses of lindstrémite. Lollingite FeAs,

Table 72. Calculated unit-cell parameters of léllingite from Jachymov for the space group Pnnm.

Table 73. Chemical analyses of léllingite.

Fig. 91. JO70P. 1 — léllingite, 2 — bismuth and bismuthinite, 3 — rammelsbergite, 4 — quartz. Adit No. 21. BSE image. Magnifica- tion 270x.

Fig. 92. J171P/L. 1 — argentite, 2 — siderite, 3 — léllingite, 4 — dolomite Zimni EliaS dump. BSE image. Magnification 230x.

Fig. 93. MP41/D. 1 — rammelsbergite, 2 — léllingite, 3 — pyrite. 4 — sphalerite. Rovnost I shaft, 8" level, Bergkittler vein. BSE image Magnification 40x.

Fig. 94. MP265A. Radial aggregates of léllingite formed at the expense of nickel-skutterudite. Both minerals rim centres of proustite corroded by chalcopyrite. 1 — léllingite, 2 — nickel-skutterudite, 3 — proustite, 4 — chalcopyrite, 5 — dolomite. Svornost shaft, 5" level, Geschieber vein. Reflected light, single polarizer. Magnification 200x.

Table 74. Calculated unit-cell parameters of magnetite from Jachymov for the space group Fd3m.

Table 75. Calculated unit-cell parameters of marcasite from Jachy- mov for the space group Panam.

Fig. 96. J171P. Ni-l6llingite triplets on (101) plane in the shape of six-pointed star. Zimni EliaS dump. SE image. Magnification 1550x. Photo A. GabaSova. Fig. 95. MP470. Euhedral and compositionally homogeneous lélling- ite crystals in gangue minerals. 1 — léllingite, 2 — dolomite. Rovnost shaft, Schweizer vein, 6" level. Reflected light, single polarizer. Magnification 260x.

Fig. 97. J171P. Ni-ldllingite triplets on (101) plane in the shape of six-pointed star (detail of broken triplets). Zimni Elia8 dump. SE image. Magnification 1890x. Photo A. GabaSova.

Fig. 98. NM9087. Lath-shaped léllingite crystals on native arsenic. SE image. Magnification 550x. Photo A. GabaSova.

Table 76. Chemical analyses of marcasite.

Fig. 99. JO83P. 1 — rammelsbergite, 2 — marcasite, 3 — sphalerite, 4 — quartz, 5 — bismuth, 6 — uraninite, 7 — matildite. Rovnost I shaft, Geist level. Magnification 160x. a) BSE image. b) Distribution of S. c) Distribution of Fe. d) Distribution of Ni. e) Distribution of As.

Fig. 101. JO34P/1. 1 — marcasite, 2 — gersdorffite. Svornost shaft, 12™ level, Geschieber vein. BSE image. Magnification 100x.

Table 79. Chemical analyses of mawsonite.

Table 78. Chemical analyses of matildite.

Table 81. Calculated unit-cell parameters of miargyrite from Jachymov for the space group Aa.

Fig. 102. J-804. Surface of subhedral miargyrite crystals. Svornost shaft, Adit level, Hildebrad vein. SE image. Magnification 670x. Photo A. GabaSova.

Table 84. Chemical analyses of millerite.

Table 83. Calculated unit-cell parameters of millerite from Jachy- mov for the space group R3m.

Fig. 103. Group of acicular millerite crystals in the gangue cavities (width of figure 2.6 cm). Photo J. & E. Sejkora.

Fig. 105. MP72/E. 1 — siderite, 2 — millerite, 3 — galena, 4 — nickel-skutterudite, 5 — Sb-gersdorffite. EliaS mine, 2A vein. BSE image. Magnification 72x. Fig. 104. J-905. Acicular crystals of millerite on dolomite. Svornost shaft, 5" level, Prokop vein. SE image. Magnification 220x. Photo A. GabaSova

Fig. 106. SR99147/r. Monazite-(Ce) along fractures in rutile in mus- covite schist. Synchisite-(Ce) aggregate in quartz-muscovite matrix. 1 — mica, 2 — rutile, 3 — monazite-(Ce), 4 — synchysite-(Ce). Skarn. Plavno mine. BSE image. Magnification 217x.

Table 85. Calculated unit-cell parameters of muscovite from Jachymov for the space group C2. Nickeline NiAs

Number of atoms based on (O, OH = 12). * HO or H calculated from crystallochemical formula. Table 86. Chemical analyses of muscovite.

Table 88. Chemical analyses of nickelite.

Table 87. Calculated unit-cell parameters of nicke- lite from Jachymov for the space group P6,/mmc.

Fig. 109. MP390A/B-2. 1 — argentite, 2 — gersdorffite, 3 — rammels- bergite. Rovnost I shaft. BSE image. Magnification 1000x.

Fig. 108. MP390A/B-1. 1 — argentite, 2 — uraninite, 3 — nickeline, 4—rammelsbergite. Rovnost I shaft. BSE image. Magnification 1150x. Fig. 107. J117P/A-10. 1 — galena, 2 — nickeline. EliaS mine, 2A vein. BSE image. Magnification 32x.

Fig. 111. MP287D. Fractured nickeline aggregate replaced by gersdorffite with varying S content. 1 — nickeline, 2 — gersdorffite, 3 — pararammelsbergite, 4 — dolomite. Barbora shaft, 5" level, vein No. 32. Reflected light, single polarizer. Magnification 65x. Fig. 110. MP483/C. 1 — nickeline, 2 — rammelsbergite, 3 — léllingite. Eva shaft, N-2 vein. BSE image. Magnification 200x.

Fig. 112. Nickeline aggregates with light grey rammelsbergite rim (width of figure 3.8 cm). Photo J. & E. Sejkora.

Fig. 113. J113P/A. 1 — nickel-skutterudite, 2 — contraction fissures. Svornost shaft, 8" level, Geschieber vein. BSE image. Magnification 115x.

Fig. 116. MP346D/4. 1 — galena, 2 — nickel-skutterudite, 3 —rammelsbergite and bismuth, 4 — quartz. Bratrstvi shaft, 3" level, Pomoc BoZi vein. BSE image. Magnification 40x.

Fig. 114. MP274A. 1 — nickel-skutterudite, 2 — porous rammelsberg- ite. Eva shaft. BSE image. Magnification 16x.

Fig. 115. MP344B. | — galena, 2 — orientated intergrowths of rammels- bergite and bismuth, 3 — nickel-skutterudite, 4 — quartz. Bratrstvi shaft, 5" level, Franti$ka vein. BSE image. Magnification 660x.

Table 89. Calculated unit-cell parameters of nickel- skutterudite from Jachymov for the space group /m3. The second type of nickel-skutterudite — cubic crystals or rather their relics partly replaced by bismuth and quartz, and some anhedral crystals, associate not only with bismuth and bismuthinite but also with tennantite, chalcopyrite and younger sulphides. Density corrected for content of bismuth and quartz was 6.23 g/cm? [429]. According to Zepharov- ich [391], density of nickel-skutterudite is 6.89 g/cm’.

Fig. 118. MP346D/2. 1 — bismuth, 2 — nickel-skutterudite, 3 — rammelsbergite and bismuth, 4 — quartz. Bratrstvi shaft, 3" level, Pomoc BoZi vein. BSE image. Magnification 72x.

Fig. 117. MP344B/1. 1 — bismuth, 2 — orientated intergrowths of rammelsbergite and bismuth, 3 — nickel-skutterudite. Bratrstvi shaft, 5" level, Franti8ka vein. BSE image. Magnification 2000x.

Fig. 119. J-902. Euhedral cubic crystals of nickel-skutterudite on dolomite. Zimni Elia8 dump. SE image. Magnification 50x. Photo A. GabaSova.

Fig. 121. Well-formed nickel-skutterudite crystals (width of figure 6.7 mm). Photo J. & E. Sejkora. Fig. 120. JO57P. Replacement of corroded nickel-skutterudite by calcite. Nickel-skutterudite zones displaced in the process are contin- uously altered in acicular millerite aggregates. 1 — nickel-skutterudite, 2 — millerite, 3 — calcite. Svornost shaft, 5th level, Prokop vein. Reflected light, single polarizer. Magnification 130x.

Table 90. Chemical analyses of nickel-skutterudite.

Table 91. Calculated unit-cell parameters of pararammelsbergite from Jachymov for the space group Pbca.

Fig. 122. J-838. Surface of radial aggregate of pararammelsbergite. Bratrstvi shaft, Zdat Buh vein. SE image. Magnification 120x. Photo A. GabaSova. Pararammelsbergite has a simple composition, it is free of increased Fe, Co, and Cu but it contains low sulphur.

Fig. 123. J-838. Detail of the surface of radial aggregate of pararammelsbergite. Bratrstvi shaft, Zdat Buh vein. SE image. Magnification 1110x. Photo A. GabaSova.

Table 93. Chemical analyses of parkerite.

Table 92. Chemical analyses of pararammelsbergite.

Parkerite occurs in grains several microns long. In re- flected light, the mineral is white to light yellow. Park- erite is intergrown with uraninite and coffinite. Radiat- ing millerite aggregates deposited on nickel-skutterudite occur in close proximity. The sample comes from the Svornost shaft, 5" level, Prokop vein.

Table 94. Calculated unit-cell parameters of phlogopite from Jachymov for the space group C2/m.

Fig. 124. JO57P. Millerite formed by alteration of skutterudite, in association with native bismuth and bismuthinite. Parkerite grain is identified in proximity of coffinitizated uraninite. | — millerite, 2 — skutterudite, 3 — bismuth, 4 — parkerite, 5 — uraninite and coffinite, 6 — dolomite. Svornost shaft, 5" level, Prokop vein. Reflected light, single polarizer. Magnification 150x.

Table 96. Chemical analyses of polybasite.

Table 95. Calculated unit-cell parameters of polybasite from Jachymov for the space group P3.

Fig. 125. J191P/1. 1 — plumbogummite, 2 — rutile, 3 — quartz. Giftkies adit. BSE image. Magnification 320.

Fig. 126. J-701. Vicinal forms on basal face of polybasite. Svornost shaft, 12level, Geschieber vein. SE image. Magnification 330x. Photo A. GabaSova.

Fig. 127. J-701. Detail of vicinal growth on basal face of polybasite. Svornost shaft, 12™ level, Geschieber vein. SE image. Magnification 330x. Photo A. GabaSova.

Fig. 129. As (apfu) vs. Sb (apfu) in pyrargyrite—proustite system in samples from Jachymov Although the two end-members are isostructural, the proustite-pyragyrite crystals from Jachymov show lim- ited miscibility (Figs 129 and 130). The limited misci- bility at this locality is probably a function of quite low temperature, possibly lower than 150 °C (see section Ore- forming processes and mineral parageneses of the Jachy- mov ore district — stability of argentopyrite) or a pres- ence of additional elements in crystals structure with possibly favoured relative separation of As and Sb in a single crystal. Our data show that at temperature lower than 150 °C, proustite can not accept more than 20 mol.% Sb, in correspondence with the empirical formula of Sb-proustite Ag,(As, ,,Sb,,,)S,- In pyrargyrite, up to 44 mol. % Sb in the Sb(As) position was observed, in cor- respondence with the empirical formula of As-pyrargy- rite Ag,(Sb, ..As, ,,)S,. The range of the As content in pyrargyrite (up to 6.02 wt.% As) is more extensive than Sb range in proustite (Sb up to 4.98 wt.%). Proustite and pyrargyrite samples used in the present study are from the Geschieber vein, Svornost shaft, 10% level (sample J-843) and 12" level (sample J-842). Crystals showing complex twinning and compositional zoning, with zones corresponding to Sb-proustite and

Fig. 130. Diagram of As content frequency in pyrargyrite—proustite series in Jachymov.

Table 97. Calculated unit-cell parameters of proustite from Jachymov for the space group R3c. Proustite-pyragyrite minerals close in composition to the end-members occur only exceptionally in the Jachymov ore veins. Pyrargyrite has at least a minor As content, with minimum at 0.2 wt.% As. Both minerals tend to form in- tergrowth in crystallographic orientation and single crys- tals of pure proustite and pyrarargyrite have not been found. Ramdohr [487] described crystallographically ori- entated intergrowth of the two minerals from Andreasberg in Harz, Germany. From Jachymov, Ramdohr mentioned

Fig. 135. Group of proustite crystals up to 1 cm (width of figure 3 cm). Photo J. & E. Sejkora.

Fig. 136. The proustite pseudomorphoses after skeletal silver crystals (width of figure 9 mm). Photo J. & E. Sejkora.

Fig. 134. Group of dark red proustite crystals up to 1-2 cm (width of figure 5 cm). Photo J. & E. Sejkora.

Fig. 137. Correlation of unit-cell parameters (a, c) and As/(As+Sb) ratio for proustite and pyrargyrite from Geschieber vein, Svornost shaft (sample No. J-842: 12" level, sample No. J-843: 10" level).

Table 98. Chemical analyses of proustite. Table 99. Calculated unit-cell parameters of pyrargyrite from Jachymov for the space group R3c. intergrowth of proustite with arsenic. Recently, crystallo- graphic intergrowths of nearly pure proustite with acanthite pseudomorphs after argentite were found in Jachymov.

Fig. 138. Pyrargyrite crystal in cavity of carbonate gangue (width of figure 3.8 cm). Photo J. & E. Sejkora. Correlation of unit-cell parameters and As/(As+Sb) ratio is in Fig. 137.

Table 100. Chemical analysis of pyrargyrite.

Fig. 139. J054P. Narrow darker growth zones of uniform width in py- rite are enriched in Ni. Content of Ni is up to 17 wt.%. 1 — pyrite, 2 — Ni-pyrite. Svornost shaft, 5" level, Prokop vein. Reflected light, single polarizer. Magnification 260.

Fig. 141. JO75P. 1 — pyrite, 2 — bornite, 3 — quartz. Svornost shaft, Daniel level, Trojicka or Geschieber vein. BSE image. Magnification 54x.

Fig. 140. JO64P. 1 — pyrite, 2 — As-pyrite. EliaS mine, sludge bed. BSE image. Magnification 40x.

Fig. 142. J105P/B-1. 1 — pyrite, 2 — dolomite. Svornost shaft, Adit level, Hildebrand vein. BSE image. Magnification 2300x.

Table 101. Calculated unit-cell parameters of pyrite from Jachymov for the space group Pa3.

Fig. 145. MP72/G-1. 1 — Sb-gersdorffite (3 wt.% Sb), 2 — Sb-gersdor- ffite (11 wt.% Sb), 3 — As-Ni-pyrite, 4 — violarite. EliaS$ mine, 2A vein. BSE image. Magnification 1150x. Fig. 144. J105P/E-1. 1 — pyrite, 2 — Sb-arsenic, 3 — dyscrasite, 4 — miargyrite. Svornost shaft, Adit level, Hildebrand vein. BSE image. Magnification 60x.

Fig. 143. J105P/B-3. 1 — pyrite, 2 — dolomite. Svornost shaft, Adit level, Hildebrand vein. BSE image. Magnification 900x.

Fig. 146. Variation of unit-cell parameter a in a set of pyrite samples enriched in As from Jachymov.

Fig. 147. Correlation of unit-cell parameter a and As content for pyrites enriched in As from Jachymov. Red symbols show data for As-free pyrite, taken from [499].

Table 104. Chemical analyses of pyrrhotite.

Table 103. Calculated unit-cell parameters of pyrrhotite from Jachymov for the space group P3,21.

Fig. 148. GLI5A/E-1. 1 — pyrrhotite, 2 — carbonate. Svornost shaft. Geschieber vein. BSE image. Magnification 540x. Quartz

Fig. 149. Tabular crystal of pyrrhotite. Zimni Elias dump, SEM. Magnification 550x. Photo A. GabaSova.

Table 105. Calculated unit-cell parameters of rammelsbergite from Jachymov for the space group Panm.

Fig. 150. Light grey rammelsbergite rims around nickeline aggregates (width of figure 2.4 cm). Photo J. & E. Sejkora.

Fig. 151. J-723. Crystals of rammelsbergite and gersdorffite on nickeline. Svornost shaft, 10" level. SE image. Magnification 670x. Photo A. GabaSova.

Fig. 154. J027P. Cores of radiating rammelsbergite aggregates, origi- nally formed by native bismuth were later replaced by bismuthinite. Sporadic Ni-pyrite crystals are enclosed in carbonate. | — bismuthin- ite, 2 — rammelsbergite, 3 — carbonate, 4 — Ni-pyrite. Svornost shaft, 10 level. Reflected light, single polarizer. Magnification 130x. Fig. 153. JO16P. Aggregates of nickeline are rimmed by zonal ram- melsbergite with varying content of S. Lath-shaped lamellae of lélling- ite are in carbonate near margin of sphalerite aggregates. 1 — sphaler- ite, 2 — rammelsbergite, 3 — nickeline, 4 — léllingite, 5 — carbonate. Bratrstvi shaft. Reflected light, single polarizer. Magnification 160x.

Fig. 152. J-723. Detail of rammelsbergite crystal. Svornost shaft, 10" level. SE image. Magnification 280x. Photo A. GabaSova.

Fig. 155. JO6OP. Radiating rammelsbergite replaced botryoidal uraninite which was at an earlier stage partly replaced by gangue with nickel-skutterudite. Arsenides are in turn replaced by galena and botryoidal sphalerite. Individual pyrite grains occur in gangue. | — ram- melsbergite, 2 — sphalerite, 3 — nickel-skutterudite, 4 — quartz. Rovnost I shaft, Geister vein. Reflected light, single polarizer. Magnification 160x.

Fig. 156. J120P/A. Rammelsbergite. Barbora shaft, 5" level, vein No. 32. BSE image. Magnification 130x.

Fig. 157. MP27/B. 1 — bismuth, 2 — uraninite, 3 — aikinite and matildite, 4 —rammelsbergite. EliaS mine. BSE image. Magnification 60x.

Fig. 158. MP27/B-1. 1 — bismuth, 2 — aikinite, 3 — matildite, 4 —uraninite. EliaS mine. BSE image. Magnification 750x.

Fig. 159. MP27/C. 1 — S-rammelsbergite, 2 — rammelsbergite. Elias mine. BSE image. Magnification 60x.

Table 106. Chemical analyses of rammelsbergite.

Table 106. (continued) The outer shape of rammelsbergite aggregates is usu- ally irregular or botryoidal and euhedral crystals are rare. Rammelsbergite rims around native metals show a zon- ing structure (Fig. 150), with individual zones showing different resistence to oxidation in air. The internal struc- ture of zoned aggregates indicates that the zones mimic shape of dendritic silver, serving as matrix for rammels- bergite. It sometimes forms radiating aggregates [351]. The present study confirmed observations by Mrna and Pavlt [351] and characterizes rammelsbergite as belong- ing to abundant minerals in the deposit. It is newly found in rims around bismuth. It also forms individual grains or larger aggregates. It shows a strong anisotropy and ag- gregate extinction in polished sections. It is often asso- ciated with nickel-skutterudite. Reported zoning of ram- melsbergite aggregates may be explained by variation in

Table 107. Unusual X-ray diffraction pattern of (Co,Fe)-rammelsbergite sample No. JO60P.

Table 108. Calculated unit-cell parameters of realgare from Jachy- mov for the space group P2,/n.

Fig. 162. Red realgar crystals on arsenic gangue (width of figure 4.4 mm). Photo J. & E. Sejkora.

Fig. 161. VS4231. 1 — realgar, 2 — bismuth, 3 — arsenic. BSE image. Magnification 115x.

Table 109. Chemical analysis of robinsonite.

Fig. 163. JIO5P/A-2. 1 — bismuth, 2 — robinsonite, 3 — nickel-skutter- udite, 4 — arsenic, 5 — calcite. Svornost shaft, Adit level, Hildebrand vein. BSE image. Magnification 160x.

Fig. 164. JO66P/2. 1 — stannite, 2 — mawsonite, 3 — roquesite. 4 — chalcopyrite, 5 — galena. Adit No. 21. BSE image. Magnificatior 800x. The sample with roquesite contains two types of stan- nite — grains enclosed in chalcopyrite, and myrmekitic particles exsolved from chalcopyrite. The two types show similar compositions with Fe/Zn ratio varying up to kés- terite. In contrast, mawsonite in rims around stannite of the first type contains low Zn up to 2 wt.%. This may indicate that domains with myrmekitic stannite represent a former unstable phase. The sample comes from the Gift- kies adit.

Table 110. Chemical analyses of roscoelite.

Fig. 165. NM4798. Texture of earthy aggregates of roxbyite. SE image. Magnification 2780x. Photo A. GabaSova

Table 111. Calculated unit-cell parameters of roxbyite from Jachymov for the space group P2/m.

Table 113. Calculated unit-cell parameters of W-Sn rutile from Jachymov for the space group P4,/mnm. ization stage, contain rutile up to 100 um long, showing sharply defined growth zones in BSE images. Light zones correspond to rutile with 4-6 wt.% W, 2-2.5 wt.% Fe, 1-1.5 % Sn and dark zones have 0.2-0.7 wt.% W, 0.9-2.4 wt.% Fe, and 0.8-1.4 % Sn. Rocks containing this zoned W-rich rutile carry topaz. A similar W-rich rutile was described from Western Australia [387] both from muscovite schist and quartz vein. It contains 7 wt.% WO,, 2 wt.% Sb,O, and 1 wt.% FeO.

Fig. 166. JO68P/D-7. 1 — xenotime-(Y), 2 — W-Sn-rutile, 3 — rutile, 4 — galena. Giftkies adit. BSE image. Magnification 720. Samples from the southeastern part of the district, which is characteristic of Sn—W sulpharsenide mineral-

Fig. 167. MP544B/G. 1 — ferberite, 2 — W-Sn-rutile, 3 — rutile, 4 — pyrite, 5 — mica. Nikolaj shaft, cross-cut to Rovnost I. BSE image. Magnification 480x.

Fig. 168. SR98553/i. Aggregate of myrmekitic intergrowth of rutile and quartz located at contact of two muscovite crystals. Variation in grey shade of rutile (resp. quartz) inclusions indicates differences in content of SiO, in rutile (resp. TiO, in quartz). 1 — quartz, 2 — rutile. Skarn. Plavno. BSE image. Magnification 600x.

Safflorite CoAs, Table 114. Chemical analyses of rutile.

Table 115. Calculated unit-cell parameters of safflorite from Jachymov for the space group Punm. Table 116. Chemical analyses of safflorite.

Fig. 170. J108P. Massive safflorite is rimmed by fine-grained radiating léllingite crystals. 1 — carbonate, 2 — safflorite, 3 — léllingite. Reflected light, single polarizer. Objective 20x. Fig. 169. VS20291. Crystals of Fe-safflorite on native bismuth. SE image. Magnification 330x. Photo A. GabaSova.

Fig. 171. J123P/A. 1 — safflorite, 2 — quartz. Svornost shaft, 10" level. BSE image. Magnification 1000x.

Number of atoms based on (Si = 6) in T-site. * B calculated from empirical formula Table 117. Chemical analyses of schorl.

Table 119. Calculated unit-cell parameters of siegenite from Jachy- mov for the space group Fd3m.

Table 118. Calculated unit-cell parameters of side- rite from Jachymov for the space group R3c.

Fig. 172. G73A/B. 1 — rammelsbergite, 2 — siderite, 3 — ankerite, 4 — calcite. Svornost shaft, Geschieber vein. BSE image. Magnification 130x. Coarse-grained light brown or dark brown siderite is a minor and scattered representative of early carbonates. Relatively well-formed rhombohedra of siderite are usually enclosed in younger carbonates, but ankerite may be enclosed in cores of some siderite crystals. Siderite in Jachymov contains minor Mn.

Table 120. Chemical analyses of siegenite. A strongly altered wall-rock contained small equant siegenite crystals with compositional zoning. The zones show variable polishing hardness. This sample contains also nickel-skutterudite and pyrite. Thin platy triangular siegenite crystals up to 0.5 mm long occurred with millerite in a vug. The crystals are whitish and strongly lustrous. The sample comes from the Svornost shaft, 5" level, Prokop vein.

Fig. 173. VS20291. Texture of a spongy aggregate of native silver. SE image. Magnification 550x. Photo A. GabaSova.

Fig. 174. J171P/B. 1 — silver, 2 — Hg-silver, 3 — dolomite. Zimni Elias dump. BSE image. Magnification 720x.

Fig. 175. MP27/A-1. 1 — silver, 2 — argentite, 3 — rammelsbergite, 4 — Hg-silver, imiterite and argentite, 5 — quartz. Elias mine. BSE image. Magnification 16x.

Fig. 176. MP27/A. | — rammelsbergite, 2 — imiterite, 3 — Hg-silver, 4 — argentite. Elid’ mine. BSE image. Magnification 1150x.

Fig. 177. MP27/A-2. 1 — silver, 2 — Hg-silver, 3 — nickeline, 4 —rammelsbergite. Elia8 mine. BSE image. Magnification 540x.

Fig. 178. MP271B/A-5. | — silver, 2 — marcasite, 3 — Fe-gersdorffite. Barbora shaft, 4''/5"" level, vein No. 32. BSE image. Magnification 1600x.

Fig. 179. MP271B. Platy aggregates of silver enriched in Hg and chalcopyrite enclosed in gangue. 1 — Hg-silver, 2 — chalcopyrite, 3 — calcite. Barbora shaft, 4/5" level, vein No. 32. Reflected light, single polarizer. Magnification 65x,

Fig. 181. The roll of silver wires in gangue cavity (width of figure 1.3 cm). Photo J. & E. Sejkora.

Fig. 180. The wire silver aggregates with acanthite coatings (width of figure 4 cm). Photo J. & E. Sejkora.

Table 123. Calculated unit-cell parameters of skut- terudite from Jachymov for the space group /m3. Table 124. Chemical analyses of skutterudite.

Fig. 182. JO87P/E. 1 — skutterudite, 2 — bismuth, 3 — sphalerite. Adit No. 1. BSE image. Magnification 160x.

Fig. 183. MP340D/A. 1 — bismuth, 2 — Ni-rich skutterudite, 3 — Co-rich nickel-skutterudite, 4 — bismuth and rammelsbergite. Plavno, vein No. 28. BSE image. Magnification 18x.

Fig. 185. J183P/1. 1 — smythite, 2 — pyrite, 3 — magnetite. Svornost shaft, 2 level, Hildebrand vein. BSE image. Magnification 400x.

Fig. 184a, b. J183P. Agregates of smythite with distinctive bireflection. Strong anisotropy in bluish white and greyish brown tints emphasizes polycrystalline texture of seemingly homogeneous crystals. Svornost shaft, 2" level, Hildebrand vein. 1 — smythite, 2 — pyrite, 3 — magnetite, 4 — ankerite, 5 — calcite. Reflected light, crossed polarizers (a) and single polarizer (b). Objective 20x.

Sphalerite ZnS Table 126. Chemical analyses of smythite.

Table 125. Calculated unit-cell parameters of smythite from Jachy- mov for the space group R3m.

Fig. 186. J183P/3. 1 —smythite, 2 — pyrite, 3 — magnetite. Svornost shaft, 2™ level, Hildebrand vein. BSE image. Magnification 540.

Fig. 187. J-444. Bipyramidal crystals od smythite on dolomite. Svor- nost schaft, 2"! level, Hildebrant vein. Magnification 245x. Photo A. GabaSova.

Table 128. Chemical analyses of sphalerite.

Table 127. Calculated unit-cell parameters of sphalerite from Jachymov for the space group F43m.

Fig. 190. J-807. Sphalerite, SE image. Magnification 900x. Photo A. GabaSova.

Fig. 189. J134P. 1 — galena, 2 — sphalerite. Svornost shaft, dump. BSE image. Magnification 80x. Fig. 188. JIOSP/F-1. 1 — sphalerite and wurtzite, 2 — dolomite. Svornost shaft, Adit level, Hildebrand vein. BSE image. Magnification 230x.

Fig. 192. J109P/3. 1 — stannite, 2 — chalcopyrite. Klement shaft. BSE image. Magnification 160x. Fig. 191. JO12P. Galena grain is rimmed by sphalerite and stannite, chalkopyrite rims sphalerite. In the right part of the sample is covel- lite after chalcopyrite and galena replaced by a secondary mineral. 1 — galena, 2 — chalcopyrite, 3 — sphalerite, 4 — stannite, 5 — Pb-sec- ondary mineral, 6 — covellite, 7 — quartz. Small old dump near Elias mine. Reflected light, single polarizer. Magnification 130x.

Table 129. Calculated unit-cell parameters of stannite from Jachymov for the space group [42m.

Table 130. Chemical analyses of stannite. of chalcopyrite and galena inclusions (Figs 191-192), and they are rimmed by pure chalcopyrite, forming struc- tures interpreted as produced by solid-state diffusion. Minute galena grains occur along border of pure chal- copyrite and myrmekite. Stannite always contains low Zn. Structural features of myrmekites may indicate orienta- tion of crystals of the original unstable phase, disintegrat- ed to myrmekite. The sample carrying roquesite contains two genetic types of stannite — independent grains enclosed in chal- copyrite and myrmekitic stannite exsolved in chalcopy- rite. Composition of the two types of stannite is compa- rable — both show Fe and Zn variation up to boundary with késterite. Mawsonite forming rims around stannite of the first type contains low Zn up to 2 wt.%. This also suggests that myrmekite domains represent an indepen- dent unstable phase.

Fig. 193. Tabular crystal of stephanite (width of figure 6.7 mm). Photo J. & E. Sejkora.

Table 133. Chemical analyses of stephanite.

Table 131. Calculated unit-cell parameters of stephanite from Jachymov for the space group Cmc2,. Table 132. Microhardness of stephanite.

Fig. 194. MP271E/A. | —sternbergite, 2 —rammelsbergite, 3 — acanthite, 4 — calcite. Barbora shaft, 4/5" level, vein No. 32. BSE image. Magnification 40x.

Fig. 197. VS7651/A. Detail from the section of the crystal. 1 — stern- bergite, 2 — pyrite (+marcasite). BSE image. Magnification 80x.

Fig. 196. VS7651/B. Section of a pseudomorph of sternbergite and pyrite (+marcasite) after an unknown mineral (“‘frieseite”?). 1 — stern- bergite, 2 — pyrite (+marcasite). BSE image. Magnification 40x. Fig. 195. MP271D. | — sternbergite, 2 — acanthite, 3 — calcite. Barbo- ra shaft, 4/5" level, vein No. 32. BSE image. Magnification 160x.

Fig. 198a, b. NM9519. 1 — sternbergite crystal parallel with section 2 — sternbergite crystal perpendicular to section, 3 — marcasite 4 — mixture of acanthite and marcasite. Reflected light, single polarize: (a), crossed polarizers (b). Magnification 50x.

Fig. 199. Group of tabular crystals of sternbergite (width of figure 1.3 cm). Photo J. & E. Sejkora.

Table 134. X-ray diffraction pattern of sternbergite (VS7651). A, &, / indices and intensity I,,, obtained from Rietveld structure refinement.

Table 136. Chemical analyses of sternbergite.

Table 135. Calculated unit-cell parameters for the space group Ccmb, density and hardness of sternbergite from Jachymov.

Fig. 200. Drawing of sternbergite crystal and twin by Haidinger [492].

The samples SRO03/1,2 represent anhedral sternbergite grains in proustite; analysed in 1986 (O. Navratil, L. Megerska). Table 136. (continued)

Table 137. Chemical analyses of stibarsen.

Fig. 201. GIL15A/F1. 1 — bismuth, 2 — stibarsen, 3 — marcasite, 4 — gersdorffite, 5 — carbonate. Svornost shaft, Geschieber vein. BSE image. Magnification 540x.

Fig. 202. JO99P/B-1. 1 — stibnite, 2 — pyrite, 3 — calcite. Svornost shaft, Adit level, Hildebrand vein. BSE image. Magnification 16x. Stibnite from Jachymov was described by Ziickert [423]. Mriia and Pavla [351] reported an isolated find of stibnite with pyrite and pyrargyrite from the Svornost shaft, Adit

Table 138. Chemical analyses of stibnite. Stromeyerite AgCuS

Fig. 204. Stibnite crystals on pyrite. Svornost shaft, Adit level, Hildebrand vein. SE image. Magnification 670x. Photo A. GabaSova. Fig. 203. Aggregates of stibnite crystals. Svornost shaft, Adit level, Hildebrand vein. SE image. Magnification 55x. Photo A. GabaSova.

Fig. 205. J-716. Stromeyerite crystals in a cavity in chalcopyrite. Svornost shaft, Daniel level, Trojicka or Geschieber vein. SE image. Magnification 1220x. Photo A. GabaSova. It was identified as aggregates of lustrous black crystals in aggregates up to 0.5 mm long (Fig. 205), deposited on chalcopyrite coating minor vugs in quartz—pyrite—chal- copyrite—bornite vein. Stromeyerite also occurs in anhe-

Fig. 206. JO58P. Aggregates of young native silver at margins of myrmekitic aggregates of stromeyerite and tetrahedrite. Irregular ag- gregates and grains of bornite are also at the margins. | — silver, 2 — bornite, 3 — stromeyerite, 4 — tetrahedrite. Svornost shaft, Daniel level, intersection of Trojicka and Geschieber veins. Reflected light, single polarizer. Magnification 130x.

Table 139. Calculated unit-cell parameters of stromeyerite from Jachymov for the space group Cmcm. Table 140. Chemical analyses of stromeyerite.

Fig. 207. MP420A/D-5. 1 — synchysite-(Ce), 2 — calcite, 3 — dolomite. Barbora shaft. BSE image. Magnification 400x.

Fig. 208. JO66P/11. 1 — Bi-tennantite, 2 — tennantite, 3 — Zn-tennantite, 4 — galena, 5 — chalcopyrite, 6 — dolomite. Giftkies adit. BSE image. Magnification 270x.

Fig. 209. MP389L. 1 — chalcopyrite, 2 — Sb-tennantite, 3 — tennantite Rovnost I shaft. BSE image. Magnification 80x.

Fig. 210. JO82P. 1 — bismuth, 2 — Bi-tennantite, 3 — tennantite, 4 — Sb-tennantite. BSE image. Magnification 200x.

Fig. 211. JO46P. Texture of repeated zones of botryoidal chalcopyrite and tennantite. Zones of chalcopyrite enriched in As may represent a submicroscopic intergrowths of chalcopyrite and tennantite. 1 — chalcopyrite, 2 — tennantite, 3 — As-chalcopyrite. Svornost shaft, 5 level, Prokop vein. Reflected light, single polarizer. Magnification 130x.

Fig. 212. JO046P. 1 — chalcopyrite, 2 — tennantite, 3 — As-chalcopyrite. Svornost shaft, 5" level, Prokop vein. Reflected light, single polarizer. Magnification 260x.

Table 141. Calculated unit-cell parameters of tennantite from Jachy- mov for the space group /43m. Table 142. Chemical analyses of tennantite.

Table 142. (continued) No. 4854. The mineral with density of 4.83 g/cm? and unit-cell parameter a = 10.357 A was shown to be iden- tical with tetrahedrite.

Table 144. Chemical analyses of tetrahedrite.

Vladimir shaft, M-2 vein, contains several tetrahedrite grains enclosed in bornite veinlet. Other well-formed tet- rahedrite crystals come from collection of National Mu- seum, Prague (Fig. 213). neous. This is shown by variation in chemical analyses, particularly in Pb, Zr and Y contents. The increased Si con- tents, interpreted in [150] by entry of Si into interlayer po- sitions along [111], could be alternatively interpreted by a heterogeneous admixture of amorphous gels SiO, - nH,O. The latter interpretation would correspond to geochemi- Tetrahedrite is rare in Jachymov though local tennan- tites contain a common admixture of Sb.

Table 145. Calculated unit-cell parameters of topas from Jachymov for the space group Pbnm. Coarse-grained parts of greisen carry euhedral topaz crys- tals, usually transparent and colourless, but fine blue crys- tals also occur. This type of greisen comes from the Rovnost I shaft, probably 8" level. Inconspicuous topaz was identified in muscovite mica schist with arsenopyrite and zoned W-rich rutile from the Nikolaj shaft, 1 level, cross cut to the Rovnost I shaft.

Fig. 213. Well-formed tetrahedrite crystals on calcite (width of figure 1.1 cm). Photo J. & E. Sejkora. Table 143. Calculated unit-cell parameters of tetrahedrite from Jachymov for the space group [43m [443].

Table 146. Calculated unit-cell parameters and density of uraninite from Jachymov.

samples SR002/1-4 represents arsenide stage, Bratrstvi mine (analyst O. Navratil, 1987). * sample contains also: (wt.%): La,O, (0.07), Gd,O, (0.10), Tb,O, (0.34)

Table 147. Chemical analyses of uraninite.

Fig. 214. Black uraninite aggregates in gangue (width of figure 6 cm). Photo J. & E. Sejkora.

Fig. 215. Uraninite vein. Magnification 1.5x. Photo J. HlouSek.

Table 148. Calculated unit-cell parameters of vaesite from Jachymov for the space group Pa3.

Fig. 217. MP430. Partly disintegrated nickel-skutterudite is replaced along growth zones by rammelsbergite and vaesite, showing variable composition and optical properties. 1 — nickel-skutterudite, 2 —rammelsbergite, 3 — S-rammelsbergite, 4 — vaesite. Barbora shaft, 5 level, vein No. 32. Reflected light, single polarizer. Magnification 260x. Fig. 216. MP295. Zoned and corroded crystals of pyrite-vaesite with internal zones of chalcopyrite. Zones with varying Fe and Ni content cannot be visually distiguished. | — chalcopyrite, 2 — Ni-pyrite, 3 — vaesite-(22%Fe), 4 — vaesite-(19%Fe), 5 — vaesite-(11%Fe), 6 — vaesite-(7%Fe), 7 — dolomite. Eva shaft, 3'! level, vein No. 2. Reflected light, single polarizer. Magnification 325x.

Fig. 218. MP175B/d. 1 — nickeline, 2 — gersdorffite, 3 — vaesite. Eva shaft, 3" level, vein No. 25. BSE image. Magnification 270x.

Table 149. Chemical analyses of vaesite.

Fig. 219. MP296/B. 1 — rammelsbergite, 2 — vaesite-pyrite, 3 — bismuthinite, 4 — dolomite. Bratrstvi shaft, 5" level, Franti8ka vein. BSE image. Magnification 400x.

Fig. 220. MP296/E. 1 — nickel-skutterudite, 2 — rammelsbergite, 3 — vaesite-pyrite, 4 — dolomite. Bratrstvi shaft, 5" level, Frantiska vein. BSE image. Magnification 130x.

Table 150. Chemical analyses of violarite.

Fig. 221. JO17P. Nickeline veinlet enclosing sphalerite is partly replaced by pyrite and rammelsbergite. Violarite forms corrosive zones around fractured nickeline in proximity of carbonate. | — As-pyrite, 2 — nickeline, 3 —rammelsbergite, 4 — violarite, 5 — sphalerite, 6 — carbonate. Bratrstvi shaft. Reflected light, single polarizer. Magnification 160x. Violarite is a rare mineral, with pink yellow or pink co- lour in polished section (Fig. 221). Sample from the Svor- nost shaft contains 50 um grain of violarite enclosed in argentite, surrounded by nickel-skutterudite. It is inter- esting that this violarite contains no Co. The sample comes from the Svornost shaft, 8" level, Geschieber vein, the southern section.

Fig. 222. Wittichenite forms exsolutions in bornite or discontinuous rims on bornite. Wittichenite is partly inter- grown with chalcopyrite and partly bound by lenticular chal- copyrite domains. Oval grains of bornite also occur inside wittichenite grains. MP112. EliaS mine, 180m level, vein A. 1 — bornite, 2 — chalcopyrite, 3 — wittichenite, 4 — quartz. Magnification a) 130x, b) 325x. Wittichenite forms an intermediate zone around sphaler- ite “eyes” (up to 50 Um in size), carrying greenockite grains. The internal zone consists of galena, while the outer zone is bismuthinite (Fig. 79). In some places

Table 151. Chemical analyses of wittichenite.

Fig. 223. MP175A/1. 1 — sphalerite, 2 — nickel-skutterudite, 3 — wittichenite, 4 — quartz. Eva shaft, 3" level, vein No. 25. BSE image. Magnification 160x.

Fig. 224. Yellow-brown xanthoconite crystals (width of figure 1.9 mm). Photo J. & E. Sejkora.

Table 152. Calculated unit-cell parameters of xanthoconite from Jachymov for the space group C2/c and density.

Table 154. Chemical analyses of xenotime-(Y).

Table 153. Chemical analyses of xanthoconite. The sample SR005 represents a crystal grown on dolomite from Jachymov collected in 1974 and analysed in 1981 (L. Megerska).

Table 155. Calculated unit-cell parameters of xenotime-(Y) from Jachymov for the space group /4,/amd.

Fig. 225. Orange xanthoconite crystals (width of figure 3.2 cm). Photo J. & E. Sejkora.

Table 156. Calculated unit-cell parameters of zavaritskite from Jachymov for the space group Pcab. (Ag, Cu, Fe), BiS,

Table 157. Chemical analyses of an unknown phase BiSb

Fig. 226. J101P. 1 — bismuth, 2 — zavaritskite. Schénerz adit. BSE image. Magnification 320x.

Fig. 227. J105P/A-1. 1 — BiSb, 2 — stibarsen, 3 — Sb-Bi-arsenic, 4 — arsenic, 5 — calcite. Svornost shaft, Adit level, Hildebrand vein. BSE image. Magnification 1300~.

Table 158. Chemical analyses of an unknown phase (Ag,Cu,Fe),BiS,. Table 159. Chemical analyses of an unknown phase Cu,AsS,.

Table 160. Chemical analyses of an unknown phase Ni,As,.

Fig. 228. VS7651. Crystals of “frieseite”. XRD analysis confirmed that the mineral is a mixture of sternbergite, pyrite and marcasite. Magnification 30x. Photo A. GabaSova. Vrba [532] studied several samples from the Hildebrand and Geister veins with sternbergite and argentopyrite. Two samples representing the two veins contained a min- eral similar to sternbergite but showing different crystal morphology. Vrba introduced the name “frieseite”’ for this

Fig. 230. NM 4807. “Frieseite” crystal parallel with section. Reflect- ed light, single polarizer. Magnification 200x. Fig. 229. VS7651. Detail of “frieseite” crystals. Magnification 170x. Photo A. GabaSova.

new mineral. It formed thick tabular crystals elongated on b axis (Figs 228, 229, 231, and 232). The samples con- tained yellow grey, slightly weathered marcasite with drusy surface, covered by pseudomorphs after pyrrhotite or sternbergite, accompanied by dolomite and minor

Fig. 231. NM 4807. “Frieseite” crystal parallel with section. Reflect- ed light, crossed polarizers. Magnification 200x.

Fig. 233. NM 4807. Tabular crystals of “frieseite” (width of figure 0.5 cm) from Jachymov. Photo A. GabaSova. Fig. 232. NM 4807. Aggregate of tabular crystals of “frieseite” from Jachymov. Magnification 20x. Photo A. GabaSova.

Fig. 234. Thick tabular singlecrystal of “frieseite” from Jachymov and a twin by Vrba [362]. Crystal forms: c(001), b(010), w(301), 1(102).

Fig. 235. Orientated intergrowth of a thick tabular crystal of “frieseite” and argentopyrite, by Vrba [362]. Crystal forms: c(001), b(010), q(043), (102), y(101), w(301), t(131).

Fig. 237. Interpretation of Mrna and Pavlu [383] — maucherite rims a fissure in nickeline, arsenide mineralization stage. Eva shaft, vein No. 39. Magnification 80x. Fig. 236. Topotactic replacement of nickeline along small fissures by orientated intergrowths of rammelsbergite (NAP), from [354]. 1 — NAP, 2 — nickeline, 3 — Ni-arsenete? Germany. Reflected light, single polarizer. Magnification 120x.

No maucherite was identified during the present study, including some original samples. Alteration of nickeline may possibly result in formation of a rare phase NAP (nickeline alteration product), described by Karup-Mgller and Makovicky [354] in an old sample from an unspeci- fied locality in Germany. The phase NAP evolves by par- tial alteration of nickeline along fractures as lamellae 2x20 um in parallel orientation. Border between NAP

Roman Skala

Journal of Geosciences, 1997

Two hundred and seven secondary mineral species are described and/or referenced. Approximately seventy secondary minerals were known from the district before the present study. All known reliable data on the individual secondary minerals from Jáchymov are presented. New and more complete X-ray powder diffraction data for compreignacite, irhtemite, lavendulan, lindackerite, masuyite, mcnearite, metaschoepite, mottramite, rabbittite, rabejacite, richetite, sodium-zippeite, voglite, zellerite, zippeite, and zýkaite are presented. A list of secondary minerals arranged according to chemical composition and list of "non-secondary" minerals are included at the end of this paper.

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History of discovery and study of new primary minerals at Jachymov

Frantisek Veselovsky

Journal of Geosciences, 2003

Jáchymov is the type locality for the following primary minerals: argentopyrite, krutovite, millerite, sternbergite, and uraninite. The history of their discovery is described in this contribution. The paper sums up the history of discovery of other type minerals at Jáchymov [560].

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History of secondary minerals discovered in Jáchymov (Joachimsthal)

Frantisek Veselovsky

Journal of the Czech …, 1997

Jáchymov is type locality for 22 minerals, including 17 secondary minerals. Data on history of discovery and description of new minerals was extracted by search in old literature. Minerals are arranged in the chronological sequence of discovery. Explanation of names of discredited or redefined minerals and some historical names is included at the end of this paper.

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A review of mineral associations and paragenetic groups of secondary minerals of the Jachymov (Joachimsthal) ore district

Frantisek Veselovsky

Journal of Geosciences, 1997

This paper presents information on relations between physical-chemical properties and genetic features for two hundred and seven secondary minerals and thirty natural phases newly discovered in the Jáchymov ore district. Eight distinct paragenetic groups are described and discussed with respect to formation conditions of the secondary minerals in the Jáchymov ore district.

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Who was who in Jachymov mineralogy II

Frantisek Veselovsky

2003

The paper presents biographic data of persons, after whom new primary minerals discovered at Jáchymov were named (K. Sternberg, W. H. Miller, G. A. Krutov), as well as the recently discovered secondary minerals (J. Vajdák, J. Èejka, J. venek). Biographies of scientists who described new minerals from Jáchymov are given in the following part (F. E. Brückmann, I. Born, A. G. Werner, H. Dauber, G. A. Kenngott, W. Sartorius v. Waltershausen, F. Sandberger, R. Nováèek, R. A. Vinogradova). Biographies of persons who significantly contributed to mineralogy of the Jáchymov ore district are presented in the last section (F. Babánek, J. tìp, R. Zückert, R. P. Dubinkina, R. V. Geceva, F. Mròa, M. Komárek, D. Pavlù). This contribution is a continuation of the 1997 article Who was who? In names of secondary minerals discovered in Jáchymov [561] dealing exclusively with secondary minerals.

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New Mineral NamesGeschieberite and SvornostiteImayoshiitePalladosilicidePlášiliteRaisaiteShchurovskyite and dmisokoloviteVanackerite

Dmitriy Belakovskiy

American Mineralogist, 2016

Two new uranyl sulfates, geschieberite (IMA 2014-006), ideally K 2 (UO 2)(SO 4) 2 (H 2 O) 2 and svornostite (IMA 2014-078), ideally K 2 Mg[(UO 2)(SO 4) 2 ] 2 •(H 2 O) 8 were recently discovered in the Geschieber vein at the Svornost mine, Jáchymov (Joachimsthal), Western Bohemia, Czech Republic, and named for their type locality. The Jáchymov ore district is a classic example of the Variscan hydrothermal vein type of deposit, so-called five-element formation, Ag-Bi-Co-Ni-U. Both new minerals are the supergene products of the post mining alteration of the uraninite and sulfides of the primary ore. They occur in the close association with each another and with adolfpateraite, gypsum and mathesiusite. Both minerals exhibit strong yellowish green fluorescence under both short-and long-wave UV radiation. Both are brittle, have an uneven fracture, and estimated Mohs hardness of ~2. Both are unstable under electron beam so the EDS mode was chosen for electron probe measurements. Geschieberite forms bright green, compact crystalline aggregates composed of multiple intergrowths of prismatic {010} crystals elongated on [001] typically 0.1-0.2 mm across sometimes modified by {001}. The crystals are translucent pale green with greenish-white streak and a vitreous luster. The cleavage is perfect on {100}. The density could not be measured due to paucity of pure material; D calc = 3.259 g/cm 3. Geschieberite is slightly soluble in cold H 2 O. It is optically biaxial (-), β = 1.596(2), γ = 1.634(4) (590 nm); X = a. In a plane-polarized transmitted light, the mineral is nearly colorless with no apparent pleochroism. The average of 7 electron probe EDS analyses is [wt% (range)]: Na 2 O 0.23 (0.12-0.59), K 2 O 14.29 (12.90-16.66), MgO 2.05 (1.77-2.52), CaO 0.06 (0-0.12), UO 3 49.51 (47.23-51.64), SO 3 27.74 (26.82-28.78), H 2 O 6.36 (by structure refinement), total 100.24. This gives the empirical formula (K 1.72 Mg 0.29 Na 0.04 Ca 0.01) Σ2.06 (U 0.98 O 2)(S 0.98 O 4) 2 (H 2 O) 2 based on 12 O apfu. The strongest lines in the X-ray powder-diffraction pattern [d Å (I%; hkl)]

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Supergene minerals at the Huber stock and Schnöd stock deposits, Krásno ore district, the Slavkovský les area, Czech Republic

Petr Ondruš

Journal of GEOsciences, 2012

This paper presents results of study of supergene minerals occuring at the Huber stock and Schnöd stock in the Krásno Sn-W ore district near Horní Slavkov (Slavkovský les area, Czech Republic). The mineralogical research is based on X-ray powder diffraction, electron microprobe analyses, optical and electron microscopy. The paper includes encyclopaedia-type presentation of the identified mineral species. The role of late hydrothermal, supergene, sub-recent and recent processes in the formation of minerals and their associations is discussed.

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Chevkinite-group minerals from Russia and Mongolia: new compositional data from metasomatites and ore deposits

Bogusław Bagiński

Mineralogical Magazine, 2012

Electron-microprobe analyses of Russian and Mongolian chevkinite-group minerals from little-known host lithologies, including various metasomatic rocks, quartzolites and an apatite deposit, are presented. The mineral species analysed include chevkinite-(Ce), perrierite-(Ce), polyakovite-(Ce) and Sr-and Zr-rich perrierite-(Ce). Compositional variation in the Sr-rich members of the group is broadly represented by the exchange vector (Fe + Mn + Al + REE) $ (Ca + Sr + Ti + Zr). Despite the varied parageneses, the chevkinite-(Ce) compositions are similar to previously published data. Many crystals have strong internal compositional variations, partly produced during primary crystallization and partly during low-temperature hydrothermal alteration.

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Multi-Analytical Characterization of Minerals of the Bowieite–Kashinite Series From the Svetly Bor Complex, Urals, Russia, and Comparison With Worldwide Occurrences

Evgenii Pushkarev

The Canadian Mineralogist, 2016

Grains of the bowieite-kashinite solid-solution series were characterized by electron microprobe analysis, single-crystal Xray diffraction, and Raman spectroscopy. The grains were recovered from dunitic rocks located in the Svetly Bor Ural-Alaskan type massif, Urals, Russia. Bowieite and kashinite occur as small inclusions (up to 100 lm in size) in isoferroplatinum grains up to 1 mm in diameter. Single-crystal X-ray diffraction data for two selected grains, with compositions (Rh 1.16 Ir 0.82 Cu 0.02 ) R2.00 S 3.00 and (Ir 1.06 Rh 0.87 Cu 0.04 ) R1.97 S 3.03 , confirm that the minerals are orthorhombic with similar cell dimensions: a 8.46(1), b 6.00(1), c 6.14(1)Å for bowieite, and a 8.46(1), b 5.99(1), c 6.14(1)Å for kashinite. The Raman spectra of the same two single grains show similar characteristic bands. One grain with composition (Ir 0.26 Rh 0.13 Pt 0.12 Ni 0.18 Cu 0.18 Fe 0.11 ) R0.98 S was found associated with the kashinite. It shows a distinctive Raman spectrum and may represent a new platinum-group mineral, although the small size (less than 20 lm) prevented us from obtaining X-ray diffraction data. Our data for the bowieite-kashinite series are compared with selected worldwide occurrences.

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Yegorovite, Na4[Si4O8(OH)4]·7H2O, a new mineral from the Lovozero alkaline pluton, Kola Peninsula

N. Zubkova

Geology of Ore Deposits, 2010

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Karel Maly

Journal of the Czech …, 2003

Ore-forming processes and mineral parageneses of the Jáchymov ore district Rudotvorné procesy a minerální pragenze jáchymovského rudního okrsku

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Who was who? In names of secondary minerals discovered in Jachymov (Joachimsthal)

Frantisek Veselovsky

Journal of Geosciences, 1997

Introduction Torbern Olof Bergman was born in Katrineberg, Sweden, the son of Barthold Bergman, sheriff on the royal estate at Katrineberg. Bergman studied mathematics, philosophy, physics and astronomy at the University of Uppsala, graduating in 1756. He later joined the faculty of the University, teaching physics and mathematics, and succeeded to Wallerius chair as Professor of chemistry in 1767. He developed a growing interest in chemistry, mineralogy and crystallography when demonstrated how the stacking of rhombohedral units could produce a scalenohedron. (Haüy later proposed the same thing but denied having known on Bergman's theories.) [217]. Jáchymov is type locality for 17 secondary minerals. Ten of these minerals were named after persons, including some prominent mineralogists of the 19th century. Interesting biographical data on these personalities were assembled during work on the projects of study of the secondary minerals in the Jáchymov ore district (Grant Agency ...

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New naturally occurring phases of secondary origin from Jachymov (Joachimsthal)

Roman Skala

Journal of Geosciences, 1997

This paper describes thirty inorganic compound-secondary mineral phases-found in the nature for the first time. All compounds come from the Jáchymov ore district. All up-to-now available physical and chemical data and references to appropriate literature are given. Crystal structure of phase [ (MoO 2) 2 As 2 O 5 (H 2 O) 2 ]. H 2 O was solved and refined, crystal structures of Ca(H 2 AsO 4) 2 and Mg-villyaellenite were refined by the Rietveld method.

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Geology and hydrothermal vein system of the Jachymov (Joachimsthal) ore district

Vladimir Srein

Journal of Geosciences, 2003

Geology and hydrothermal vein system of the Jáchymov (Joachimsthal) ore district Geologie a hydrotermální ilný systém jáchymovského rudního okrsku (26 figs, 1 tab) This contribution provides a brief review of geology of the Kruné hory Mts. (Erzgebirge) and specifically of the Jáchymov (Joachimsthal) deposit. Main types of rocks in the Jáchymov ore district and the role of tectonic processes are described. The position of the ore district is defined much like its tectonic borders. Geological factors controlling the mineralization (especially the so-called five-element mineralization) are summarized. Hydrothermal veins are divided into Morning and Midnight veins according to the classical historical speak of miners, and all vein clusters are listed. Vein hydrothermal five-element mineralization is chronologically divided into separate mineralization stages and their age is estimated.

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Partizansky base-metal skarn deposit, Dal’negorsk ore district, Russia: Stages of ore formation, mineral assemblages, and typomorphism of fahlore

Ludmila Simanenko

Geology of Ore Deposits, 2006

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Mineralogy and Geochemistry of Ores of the Kedrovskoe-Irokinda Ore Field (Northern Transbaikalia

Olga Plotinskaya

Russian Geology and Geophysics, 2019

Ore mineralogy of the Kedrovskoe-Irokinda ore field (northern Transbaikalia) has been studied. The ore field comprises ca. 200 quartz veins. Vein 3 and the Kvartsevaya and Serebryakovskaya veins of the Irokinda deposit and the Shamanovskaya, Pineginskaya, Osinovaya, and Barguzinskaya veins of the Kedrovskoe deposit have been described. Quartz-pyrite assemblage (quartz-1, pyrite, pyrrho-tite, and marcasite) and quartz-gold-sulfide assemblage (quartz-2, galena, chalcopyrite, sphalerite, electrum, fahlore, Ag tellurides, and sulfosalts of Ag, Cu, Sb, Pb, and Sn) have been revealed. Major ore minerals were investigated by EPMA and LA-ICP-MS. An increase in Ag content in electrum (from 5.5 to 72.4 wt.%) and fahlores (from 5 to 35 wt.%) and in the abundance of Ag minerals during the ore formation has been established. Galena contains impurities of Sb and Ag (thousands of ppm), Se, Cd, Te, and Bi (hundreds of ppm), Cu, Zn, As, and Sn (tens of ppm). It is shown that the Kedrovskoe-Irokinda ore field is a rare type of orogenic deposits with considerable variations in the composition of major ore minerals (electrum, sphalerite, and fahlores), which is explained by the diversity of the host rocks.

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www.jgeosci.org Journal of Geosciences, 54 (2009), 373–384 DOI: 10.3190/jgeosci.057 Original paper New data for metakirchheimerite from Jáchymov

Viktor Goliáš

2015

Metakirchheimerite was found only on a few samples from the Jan Evangelista vein at the “Adit level ” of the Svornost

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History of the Jachymov (Joachimsthal) ore district

Frantisek Veselovsky

Journal of Geosciences, 1997

Jáchymov was founded in 1516 in place of the former abandoned village Konradsgrün, following discovery of a rich silver deposit. During the first twenty years, the town witnessed a remarkable boom, becoming in 1534 the second largest town in Bohemia, second only to Prague. Jáchymov became an important cultural centre, hosting Agricola, Mathesius and many outstanding personalities of the time. Latin school was founded in Jáchymov; a major part of library assembled in this school was preserved till present. The coins minted in Jáchymov were named after the German name of the town "Thaler", later "tolar", the name which during time was adopted as the name of the USA currency. A mining school was founded in Jáchymov in 1716. The history of the town witnessed periods of expansion and episodes of decline due to wars, fires, plague epidemic waves, and economic problems. The original interest in silver was substituted by mining of cobalt and nickel, later on, uranium was used for production of uranium colours and separation of radium compounds for medical application. The last major mining expansion took place after the Second World War, with extensive mining and ore dressing of uraninite and its exports to USSR. The ore district was exhausted and mining terminated by 1964. Springs of radioactive water taped in the mines are used since 1906 for curative application in local spa.

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ORYKTOLOGIKA NEA-NEWS ON MINERALS , January-February 2014

Dimitris Minatidis

A rare , unique , Gem Rubellite Tourmaline from Pala mine in California , USA .

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Andradite from Pb-Zn Djurkovo deposit, Central Rhodopes: chemical composition and U/Pb datin

Valentin Grozdev

Review of the Bulgarian Geological Society, 2020

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