Uraninite
Uraninite is an oxide mineral recognized among collectors for its crystal form and distribution, with notable Chinese occurrences.
About Uraninite
Uraninite is an oxide mineral in the uraninite group / fluorite supergroup and has the chemical formula UO2 (to UO2.67). It crystallizes in the isometric system and holds a steady position among oxide species.
Identification & care
Crystals commonly develop as cubic crystals (octahedra or cubes) — relatively rare; typically massive (pitchblende — resinous, botryoidal); also disseminated. Its color range is broad, including black, brownish-black, grayish-black (pitchblende/massive), and gray to greenish-brown (altered). The luster is sub-metallic, greasy, dull (massive pitchblende), the streak is grayish to olive-brown, and specimens are typically opaque. The cleavage is indistinct {001}. The fracture is conchoidal to uneven; often metamict, which aids identification.
Collector context
Collector notes
Among collectors of crystallized species, Uraninite is a recognized reference. Documented Chinese occurrences are recorded at Xihuashan ore field, among others.