Calcite – Blue

Scientific Name: Calcium carbonate

Group: Carbonates

Chemical composition: CaOCO2; Mn, Fe, and Mg may partially replace the Ca

Colors: pale to deep blue

Hardness: 3

Formation: Rhombohedral and scalenohedral crystals. Twinning is common.

Principal Sources: Worldwide

Special Notes: Calcite is one of the most important minerals. It is extremely common and found throughout the world in sedimentary, metamorphic and igneous rocks. In the form of limestone and marble it makes up a significant portion of Earth’s crust and serves as one of the largest carbon repositories on our planet. The properties of calcite make it extremely useful as: construction materials, abrasives, agricultural soil treatments, construction aggregates, pigments, pharmaceuticals and more. Calcite is the main element in limestones and marbles.