Wavellite on Quartz

In the early 1970’s (Ken found this one in 1973) the only known find of California wavellites was discovered on Slate Mountain. The wavellite was found on platy rock matrix, and occasionally coating quartz. This example has a smoky quartz which was likely completely coated, but when recovered lost some of it to reveal the quartz crystal inside. A very rare opportunity to grab such a rarity! Ex Ken Roberts collection.

Locality: Slate Mountain, El Dorado County California

Composition: aluminium basic phosphate  Al₃(PO₄)₂(OH, F)₃·5H₂O