2" Sharp, Scalenohedral Calcite Crystal Cluster - Red Dome Mine
This is a cluster of sharp, scalenohedral calcite crystals collected from the Red Dome Mine in Australia. Due to the closure of this mine, it can be difficult to come across these stunning calcite crystals. The impurities within the crystals that give them their faint orange hue can likely be attributed to cuprite.
Calcite, CaCO3, is a carbonate mineral and the most stable polymorph of calcium carbonate. The other polymorphs are the minerals aragonite and vaterite. Calcite crystals are trigonal-rhombohedral, though actual calcite rhombohedra are rare as natural crystals. However, they show a remarkable variety of habits including acute to obtuse rhombohedra, tabular forms, and prisms. Calcite exhibits several twinning types adding to the variety of observed forms. It may occur as fibrous, granular, lamellar, or compact. Cleavage is usually in three directions parallel to the rhombohedron form.
Red Dome Mine, Mungana, Queensland, Australia
Cluster: 2 x 1.6"