Calcite blue tactile 139g, Madagascar

The composition of blue calcite from Madagascar is based on the basic chemical composition of calcite, which is a carbonate mineral. The chemical formula of calcite is CaCO₃, which means it is composed of calcium (Ca), carbon (C), and oxygen (O). The blue color of blue calcite is usually due to the presence of various trace elements, especially copper. Since blue calcite can have different shades of blue, this may indicate a different concentration or type of impurity. Blue calcite crystals often form in a hexagonal form and can be transparent to semi-transparent.