Cornwallite over Chrysocolla on Quartz (rare CA) Trimingham

Item Description

Mineral specimens are uncommon from this obscure Nevada County district. This showy, colorful and rare combination features a thin crust of bubbly, lustrous, rich blue-green cornwallite over a thin crust of chrysocolla on massiv quartz matrix. Cornwallite is a rare Cu-arsenate that is the arsenate analogue of pseudomalachite and the monoclinic dimorph of cornubite. Excellent, highly representative and seldom available combination material from Bob Trimingham.