Petzite

Ag3 AuTe2
c 2001-2005 Mineral Data Publishing, version 1

Crystal Data: Cubic. Point Group: 432.
shaped blebs, to 2 mm.

Massive, fine granular to compact and as irregularPhysical Properties: Cleavage: {001}. Fracture: Subconchoidal. Tenacity: Slightly sectile tobrittle. Hardness = 2.5–3 VHN = 48 (10 g load). D(meas.) = 8.7–9.4 D(calc.) = 8.74
Optical Properties: Opaque. Color: Bright steel-gray to iron-gray to iron-black, commonly
tarnished from bronze-yellow to sooty black; in reflected light, grayish white with a pale bluishtint. Luster: Metallic. Anisotropism: Noticeable in part.
R: (400) 45.0, (420) 43.7, (440) 42.4, (460) 41.4, (480) 40.6, (500) 39.9, (520) 39.3, (540) 38.8,(560) 38.5, (580) 38.3, (600) 38.2, (620) 38.1, (640) 38.0, (660) 37.8, (680) 37.8, (700) 37.8
Cell Data:

Space Group: I41 32. a = 10.385(4)Z=8X-ray Powder Pattern: Botés, Romania.
2.77 (100), 2.12 (80), 2.03 (70), 2.44 (60), 2.32 (60), 7.31 (50), 1.893 (50)
Chemistry:AgAu
TeHgCu(1)
41.37
23.42
33.00
2.26
0.16

(2)
41.87
25.16
33.21

(3)
41.71
25.39
32.90

Total 100.21
100.24100.00(1) Kalgoorlie, Australia. (2) Mother Lode district, California, USA. (3) Ag3 AuTe2 .
Occurrence:With other tellurides in vein-controlled gold deposits.

Association: Gold, hessite, sylvanite, krennerite, calaverite, altaite, montbrayite, melonite,frohbergite, tetradymite, rickardite, vulcanite, pyrite.
Distribution: Noted in small amounts at a number of localities other than those listedhere. In Romania, from Săcărı̂mb (Nagyág) [TL], Botés, and Baia Sprie (Felsőbánya). At theKochbulak gold deposit, Chatkal-Kuramin Mountains, eastern Uzbekistan. From the Byn’govsk
Au–Te deposit, Central Ural Mountains, Russia. In the Zhana-Tyube Au–Te deposit, northern
Kazakhstan. In the USA, at Gold Hill, Boulder Co., Lake City, Hinsdale Co., and Leadville,
Lake Co., Colorado; from California, in the Golden Rule and Norwegian mines, Tuttletown, andthe Jamestown mine, Tuolumne Co., in the Stanislaus and Melones mines, Carson Hill district,Calaveras Co., and in other mines along the Mother Lode; from the Buster mine, Olinghouse
district, Washoe Co., and elsewhere in Nevada. In Canada, at the Hollinger mine, Timmins,
and the Lake Shore mine, Kirkland Lake, Ontario; in Quebec, at the Robb-Montbray mine,
Montbray Township, the Noranda mine at Rouyn, the Horne mine at Noranda, and many otherlocalities. From El Indio, east of Coquimbo, Chile. At Kalgoorlie, Western Australia. From theTuvatu Au–Ag–Te deposit, Viti Levu, Fiji Islands. At the Bulawan deposit, Negros Occidental,Phillipines.
Name:After W. Petz, who first analyzed the mineral.

Type Material: Harvard University, Cambridge, Massachusetts, 99348; National Museum of
Natural History, Washington, D.C., USA, R9556.
References: (1) Palache, C., H. Berman, and C. Frondel (1944) Dana’s system of mineralogy,(7th edition), v. I, 186–187. (2) Frueh, A.J., Jr. (1959) The crystallography of petzite, Ag3 AuTe2 .
Amer. Mineral., 44, 693–701. (3) Chamid, S., E.A. Pobedimskaya, E.M. Spiridonov, andN.V. Belov (1978) Refinement of the structure of petzite AuAg3 Te2 . Kristallografiya (Sov.
Phys. Crystal.), 23, 483–486 (in Russian). (4) Criddle, A.J. and C.J. Stanley, Eds. (1993)
Quantitative data file for ore minerals, 3rd ed. Chapman & Hall, London, 434.
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