Olivenite forms as a layer on top of copper sulfides.

Chemical Formula: Cu2+2(AsO4)(OH)
Class: Arsenates
Hardness: 3
Coloration: Gray, green, yellow, white

How to identify it/Unique Characteristics or Properties:
Olivenite forms as a layer on top of copper sulfides, and so is not a thick layer. It generally is recognized by it’s tiny green crystal “puff balls” but can also form larger crystals. Olivenite was first identified in Cornwall England’s copper mines and was often found there.

Where to find it in…

The Northwest: N/A
Other: England, Slovakia, Namibia
Past Uses: Manganese ore.
How it was Made: Forms as a layer on copper ore where there are pockets of air against the copper.
Interesting Facts: Olivenite can also look like splinters of wood growing on the copper.