These calcites are from the Denton Mine in the Goose Creek Mine Group, Harris Creek Sub-District, Kentucky Fluorspar District, Cave In Rock, Hardin County, Illinois, USA. Seven different minerals have been identified at this mine including calcite. Calcite is a carbonate containing Ca, C and O. This is a cluster of scalenohedral calcites with the main crystal being twinned and double terminated. It measures 4 3/4 x 3 1/2 x 3 inches or 120 x 88 x 76 mm.