Cuprobismutite

Cu8 AgBi13 S24
c 2001-2005 Mineral Data Publishing, version 1Crystal Data: Monoclinic. Point Group: 2/m. Massive and as prismatic crystals and thinblades, to 1 mm, slightly twisted k [010], the elongation axis.
Physical Properties:Hardness = n.d. VHN = n.d. D(meas.) = 6.36 D(calc.) = [6.24]

Optical Properties: Opaque. Color: Gray, commonly tarnished to bluish. Luster: Metallic.
Anisotropism: Distinct.
R1 –R2 : (400) 31.8–35.2, (420) 32.4–35.8, (440) 33.1–36.4, (460) 34.4–37.6, (480) 34.9–37.6, (500)34.9–38.0, (520) 35.4–38.4, (540) 35.9–38.9, (560) 36.2–39.4, (580) 36.6–39.8, (600) 36.8–40.1, (620)37.0–40.4, (640) 37.2–40.4, (660) 37.2–40.5, (680) 37.2–40.5, (700) 37.2–40.5
Cell Data: Space Group: C2/m. a = 17.520(1)β = 100.18(1)◦ Z = [2]b = 3.926(3)c = 15.261(1)

X-ray Powder Pattern: Hall’s Valley, Colorado, USA.
3.10 (10), 2.73 (6), 3.65 (4b), 4.31 (3), 1.961 (3), 1.719 (3), 6.24 (2)Chemistry:CuAgPbZnMnFe(1)
15.96
0.89

(2)
15.1
1.19
0.84

0.10
0.14
2.13

(3)
12.39
2.63BiSbSeTeS
Total

(1)
60.80

(3)
66.22

[19.94]

(2)
63.8
0.08
0.50
0.07
18.5

[99.82]100.2

100.0018.76(1) Hall’s Valley, Colorado, USA; analysis by Hillebrand (in 1884), who assumed the sample
to contain chalcopyrite 6.97% after deducting gangue 4.43%; sulfur content “calculated for theanalysis”; then corresponds to Cu9.69 Ag0.32 Zn0.06 Bi11.23 S24.00 . (2) Ohio district, Utah, USA; byelectron microprobe, corresponds to Cu9.77 Ag0.45 Pb0.17 Mn0.10 (Bi12.55 Sb0.03 )Σ=12.58 (S23.72 Se0.26
Te0.02 )Σ=24.00 . (3) Cu8 AgBi13 S24 .
Occurrence:

Rare, of hydrothermal origin with other sulfides and sulfosalts.

Association: Emplectite, aikinite, wittichenite, benjaminite, berryite, cupropavonite, paděraite,
hodrushite, wolframite, bismuthinite.
Distribution: In the USA, in Colorado, from the Missouri mine, Hall’s Valley, Park Co. [TL],and at Silver Cliff, Custer Co.; in the Fairfax quarry, Centreville, Fairfax Co., Virginia; andfrom the Tunnel Extension 2 mine, Marysvale, Ohio district, Piute Co., Utah. From Krupka,Czech Republic. At Băiţa (Rézbánya) and in the Paulus mine, Ocna de Fier (Morávicza; Vaskő),Romania. From Baicolliou, Switzerland.
Name:

For copper, CUPRum, and BISMUTh in the composition.

Type Material: Harvard University, Cambridge, Massachusetts, 94989; National Museum ofNatural History, Washington, D.C., USA, 92902.
References: (1) Palache, C., H. Berman, and C. Frondel (1944) Dana’s system of mineralogy,(7th edition), v. I, 437. (2) Nuffield, E.W. (1952) Studies of mineral sulfo-salts: XVI
Cuprobismuthite [sic]. Amer. Mineral., 37, 447–452. (3) Taylor, C.M., A.S. Radtke, and C.L.
Christ (1973) New data on cuprobismutite. J. Res. U.S. Geol. Sur., 1, 99–103. (4) Ozawa,T. and W. Nowacki (1975) The crystal structure of, and the bismuth-copper distribution insynthetic cuprobismuthite [sic]. Zeits. Krist., 142, 161–176. (5) Cook, N.J. and C.L. Ciobanu(2003) Lamellar minerals of the cuprobismutite series and related paděraite: a new occurrence
and implications. Can. Mineral., 41, 441–456. (6) Berry, L.G. and R.M. Thompson (1962) X-ray
powder data for the ore minerals. Geol. Soc. Amer. Mem. 85, 143–144. (7) Criddle, A.J. and C.J.
Stanley, Eds. (1993) Quantitative data file for ore minerals, 3rd ed. Chapman & Hall, London,126.
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