Mineral Factbook

Ullmannite

NiSbSIMA symbol: Ullgrandfathered

Ullmannite is a sulfide or sulfosalt mineral with the formula NiSbS, crystallizing in the cubic system. It has a Mohs hardness of 5-5.5, typically white or gray in color, with a metallic luster, a specific gravity of 6.2-6.7. Its streak is black or gray.

Photos

Ullmannite specimen photo
Kaarel Tiidus · CC BY-SA 4.0 · Commons
Ullmannite specimen photo
Nessa Eull · CC0 · Commons
Ullmannite specimen photo
Henk Smeets – tomeikminerals.com · CC BY 4.0 · Commons
Ullmannite specimen photo
Andrew Silver · Public domain · Commons

Crystallography

Crystal systemcubic crystal systemWikidata (CC0)
Space groupP 21 3
Cell (Å, °)a = 5.9341, b = 5.9341, c = 5.9341; α = 90, β = 90, γ = 90
Cell volume208.961 ų, Z = 4
Axial ratios1.0000:1:1.0000calculated from COD 9012259
Source structureCOD 9012259 (Journal of Solid State Chemistry, 2001) — 1 of 7 structures

Powder X-ray diffraction (calculated)

2θ (degrees, Cu Kα1)I/I₀ (max 100)
d (Å)2.6542.4231.7891.5864.1961.102
I/I₀10056.348.73023.420.3

xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9012259; idealized occupancies, no preferred orientation.

Physical properties

Density (calculated)6.755 g/cm³calculated from COD 9012259
Hardness (Mohs)
5-5.5single sourceDana, System of Mineralogy, 6th ed. (1892)
Specific gravity
6.2-6.7 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892)
Color
gray, 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 weight212.52 g/molcalculated from the IMA formula
Composition (wt%)Ni 27.62%, Sb 57.29%, S 15.09%

Classification

Nickel-Strunz (10th)2.EB.25Wikidata (CC0)
Nickel-Strunz (9th)2.EB.25Wikidata (CC0)
Dana (8th)2.12.3.3Wikidata (CC0)