Tyuyamunite Locality: Ridenaur Mine (Ridenour Mine), Prospect Canyon District, Coconino County, Arizona, USA (Locality at mindat.org) Size: 13.5 x 7.7 x 6.1 cm. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Tyuyamunite
A canary-yellow calcium uranyl vanadate — a carnotite-group uranium mineral.
Intro adapted from Wikipedia (CC BY-SA).
Tyuyamunite is an IMA-recognized mineral species in the vanadate class, with the chemical formula Ca(UO₂)₂(VO₄)₂·5-8H₂O.
It crystallizes in the tetragonal crystal system.
Key properties: Mohs hardness 2; specific gravity 3.57–4.35; typically yellow or green; yellow streak; Adamantine, pearly on {001}, may be dull to waxy if massive luster; optically biaxial.
IMA symbol Tyu, grandfathered status — known before the IMA’s founding, named in 1912.
Occurs as an uncommon mineral in the oxidized zone of U–V deposits, especially those of the Colorado Plateau-type.
It is found associated with Metatyuyamunite, carnotite, corvusite, uranophane, volborthite, gypsum.
The name refers to the Tyuya-Muyun Cave, Kyrgyzstan, its original locality.
Collections: Collector Favorites, Rare & Remarkable, Fluorescent & Glowing.