This cobaltoian calite is from the Katanga Copper Crescent in Katanga, Democratic Republic of the Congo. This is a vast mineral rich area that is mined, primarily, for the recovery of copper and other metals. There are over 100 different mines and diggings in this area with 10 large operations. Local people mine in the closed locations for a long list of mineral specimens including the associated minerals such as cobaltoan calcite. It is the cobalt rich variety of calcite, a carbonate, and it contains the elements Ca, Co, C and O. This specimen consists of a mostly quartz matrix that contains an exposed surface that is covered with transluscent to transparent rhombic crystals. The crystals have a bright glistening luster and are damage free. This piece measures 3 1/2 x 2 1/4 x 2 inches or 92 x 60 x 50 mm.