FORNACITE - (Pb,Cu)3[(Cr,As)O4]2(OH) usally occurs associated with dioptase. Fine micro crystals of Fornacite. From Lone Star Mine, Copperopolis, Yavapai Co., Arizona. Specimen is 1-1/2"wide x 1-1/2" deep x 1" thick. Require a microscope to see the tiny olive green prismatic crystals.