Pyrite Cube on Basalt from Gilman District, Eagle County, Colorado, USAThree large cubic pyrite crystal across inter grown perched on Basalt matrix. The pyrite crystals have smooth faces and sharp edges, stands upright nicely without additional support. A must have for any collection, these unique formations are formed through a process of precipitation and crystal growth within sedimentary and metamorphic rocks, taking millions of years and resulting in nearly perfect cubic shaped crystals. You will receive the exact