- Tyuyamunite, Volborthite
- Cabinet, 13.5 x 6.5 x 5.2 cm
- Ridenaur Mine (Ridenour Mine), Prospect Canyon District, Coconino Co., Arizona, USA
This bright cabinet specimen is richly covered with canary-yellow, discrete microcrystals of the hydrated uranyl vanadate tyuyamunite. One side of the piece also has sparkly, forest-green volborthite microcrystals with tyuyamunite. Volborthite is an uncommon hydrated copper vanadate secondary mineral found in the oxidized zones of vanadium-bearing hydrothermal deposits. This is an excellent, large combination specimen on blocky, sandstone matrix of these uncommon species.