CALCITE on AMETHYST, Minas Gerais BRAZIL (large cabinet)

Calcite is a carbonate mineral and the most stable form of calcium carbonate (CaCO3). It is widely found, especially as a key element in limestone. With a hardness rating of 3 on the Mohs scale, calcite is assessed based on its ability to be scratched. Large crystals of calcite are utilized in optical devices, while limestone, primarily made up of calcite, serves a variety of purposes.