3.9" Yellow, Calcite Crystal - Morocco
This is a honey colored "beam calcite" crystal that's part of a new find from the Atlas Mountains of Morocco. This specimen is 3.9" wide and has a pale golden-yellow coloration. The lines across the calcite run along natural points of cleavage and likely occurred as a result of the cleaning process.
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.