Mineral Factbook

Uraninite

UO2IMA symbol: Urngrandfathered

Uraninite is an oxide or hydroxide mineral with the formula UO2, crystallizing in the cubic system. It has a Mohs hardness of 5.5, a specific gravity of 8.

Photos

Uraninite specimen photo
Mai Seppel · CC BY-SA 4.0 · Commons
Uraninite specimen photo
Mai Seppel · CC BY-SA 4.0 · Commons
Uraninite specimen photo
James St. John · CC BY 2.0 · Commons
Uraninite specimen photo
James St. John · CC BY 2.0 · Commons

Crystallography

Crystal systemcubic crystal systemWikidata (CC0)
Space groupF m -3 m
Cell (Å, °)a = 5.4682, b = 5.4682, c = 5.4682; α = 90, β = 90, γ = 90
Cell volume163.506 ų, Z = 4
Axial ratios1.0000:1:1.0000calculated from COD 9009049
Source structureCOD 9009049 (Crystal Structures, 1963) — 1 of 2 structures

Powder X-ray diffraction (calculated)

2θ (degrees, Cu Kα1)I/I₀ (max 100)
d (Å)3.1571.9331.6492.7341.2541.116
I/I₀10049.547.437.320.217.7

xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9009049; idealized occupancies, no preferred orientation.

Physical properties

Density (calculated)10.969 g/cm³calculated from COD 9009049
Hardness (Mohs)
5.5single sourceDana, System of Mineralogy, 6th ed. (1892)
Specific gravity
8 g/cm3single sourceDana, System of Mineralogy, 6th ed. (1892)

Chemistry (calculated)

Molecular weight270.03 g/molcalculated from the IMA formula
Composition (wt%)U 88.15%, O 11.85%

Classification

Nickel-Strunz (10th)4.DL.05Wikidata (CC0)
Nickel-Strunz (9th)4.DL.05Wikidata (CC0)
Dana (8th)5.1.1.1Wikidata (CC0)