Blue Calcite

Hardness of 3 on the Mohs scale, pale blue to greyish-blue color, vitreous to pearly luster, trigonal crystal system, and perfect rhombohedral cleavage.

Forms primarily in sedimentary environments through the precipitation of calcium carbonate from marine waters or hydrothermal veins.

Used widely in decorative carvings, tumbled stones, spiritual crystal healing practices, and as a calcium source in various industrial applications.

Calcite exhibits strong double refraction, meaning objects viewed through clear specimens appear doubled. Blue coloration is caused by trace inclusions of other minerals like copper or structural defects.

Easily identified by its characteristic rhombohedral cleavage and strong effervescence when tested with dilute hydrochloric acid. Found globally with notable deposits in Madagascar and Mexico.