Mineral Factbook

Petzite

Ag3AuTe2IMA symbol: Ptzgrandfathered

Petzite is a sulfide or sulfosalt mineral with the formula Ag3AuTe2, crystallizing in the cubic system. It has a Mohs hardness of 2.5-3, typically black or gray in color, with a metallic luster, a specific gravity of 8.7-9.02.

Photos

Petzite specimen photo
Vikent’eva, O.V.; Shilovskikh, V.V.; Shcherbakov, V.D.; Vikentyev, I.V.; Bortnikov, N.S. · CC BY 4.0 · Commons
Petzite specimen photo
Didier Descouens · CC BY-SA 3.0 · Commons
Petzite specimen photo
Robert M. Lavinsky · CC BY-SA 3.0 · Commons
Petzite specimen photo
Robert M. Lavinsky · CC BY-SA 3.0 · Commons

Crystallography

Crystal systemcubic crystal systemWikidata (CC0)
Space groupI 41 3 2
Cell (Å, °)a = 10.38, b = 10.38, c = 10.38; α = 90, β = 90, γ = 90
Cell volume1118.39 ų, Z = 8
Axial ratios1.0000:1:1.0000calculated from COD 9000084
Source structureCOD 9000084 (American Mineralogist, 1959)

Powder X-ray diffraction (calculated)

2θ (degrees, Cu Kα1)I/I₀ (max 100)
d (Å)2.7742.1197.342.0362.3211.895
I/I₀10051.33532.930.826.5

xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9000084; idealized occupancies, no preferred orientation.

Physical properties

Density (calculated)9.215 g/cm³calculated from COD 9000084
Hardness (Mohs)
2.5-3single sourceDana, System of Mineralogy, 6th ed. (1892)
Specific gravity
8.7-9.02 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892)
Color
black, graysingle sourceDana, System of Mineralogy, 6th ed. (1892)
Luster
metallicsingle sourceDana, System of Mineralogy, 6th ed. (1892)

Chemistry (calculated)

Molecular weight775.77 g/molcalculated from the IMA formula
Composition (wt%)Ag 41.71%, Au 25.39%, Te 32.9%

Classification

Nickel-Strunz (10th)2.BA.75Wikidata (CC0)
Nickel-Strunz (9th)2.BA.40aWikidata (CC0)