Calcite, Chalcopyrite - Sweetwater Mine, Reynolds County, Missouri, USA
 
 8.4 cm long calcite scalenohedron on matrix from the Sweetwater Mine in the state of Missouri. The crystal clearly dominates the specimen both by its size and its intense color, and is superbly presented by rising vertically from the matrix. Characteristic for the locality, this piece convinces with a good luster and a golden-yellow color of the calcite. Size 12.4 cm x 9.1 cm