Mineral Factbook

Cobaltite

CoAsSIMA symbol: Cbtgrandfathered

Cobaltite is a sulfide or sulfosalt mineral with the formula CoAsS, crystallizing in the orthorhombic system. It has a Mohs hardness of 5.5, typically white, black, gray or red in color, with a metallic luster, a specific gravity of 6-6.3. Its streak is black or gray.

Photos

Cobaltite specimen photo
Osama Shukir Muhammed Amin FRCP(Glasg) · CC BY-SA 4.0 · Commons
Cobaltite specimen photo
James St. John · CC BY 2.0 · Commons
Cobaltite specimen photo
James St. John · CC BY 2.0 · Commons
Cobaltite specimen photo
Darla Sondrol · CC0 · Commons

Crystallography

Crystal systemorthorhombic crystal systemWikidata (CC0)
Space groupP c a 21
Cell (Å, °)a = 5.5833, b = 5.5892, c = 5.5812; α = 90, β = 90, γ = 90
Cell volume174.168 ų, Z = 4
Axial ratios0.9989:1:0.9986calculated from COD 9004218
Source structureCOD 9004218 (The Canadian Mineralogist, 1990) — 1 of 7 structures

Powder X-ray diffraction (calculated)

2θ (degrees, Cu Kα1)I/I₀ (max 100)
d (Å)2.4972.2811.6831.6852.4991.684
I/I₀10088.38281.881.281.2

xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9004218; idealized occupancies, no preferred orientation.

Physical properties

Density (calculated)6.328 g/cm³calculated from COD 9004218
Hardness (Mohs)
5.5single sourceDana, System of Mineralogy, 6th ed. (1892)
Specific gravity
6-6.3 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892)
Color
black, gray, red, violet, whitesingle sourceDana, System of Mineralogy, 6th ed. (1892)
Streak
black, graysingle sourceDana, System of Mineralogy, 6th ed. (1892)
Luster
metallicsingle sourceDana, System of Mineralogy, 6th ed. (1892)

Chemistry (calculated)

Molecular weight165.92 g/molcalculated from the IMA formula
Composition (wt%)Co 35.52%, As 45.16%, S 19.33%

Classification

Nickel-Strunz (10th)2.EB.25Wikidata (CC0)
Nickel-Strunz (9th)2.EB.25Wikidata (CC0)
Dana (8th)2.12.3.1Wikidata (CC0)