- Volborthite, Tyuyamunite
- Cabinet, 15.0 x 11.2 x 6.0 cm
- Ridenaur Mine (Ridenour Mine), Prospect Canyon District, Coconino Co., Arizona, USA
Volborthite is an uncommon hydrated copper vanadate secondary mineral found in the oxidized zones of vanadium-bearing hydrothermal deposits. This bright, large cabinet specimen is richly covered with tiny, sparkly, forest-green volborthite blades and canary-yellow, discrete microcrystals of the hydrated calcium uranyl vanadate tyuyamunite. This is an excellent, large combination specimen on blocky, sandstone matrix of these uncommon species.