Dolomite was named after the French mineralogist Déodat de Dolomieu and is widely found in sedimentary rock formations known as dolostone. It occurs in two forms: a chemically uniform mineral with the formula CaMg(CO₃)₂, and dolomitic limestone, which contains a mixture of calcium and magnesium carbonates.

Dolomite is believed to form through the replacement of calcium with magnesium in limestone during lithification—a natural process where sediments like shells from marine organisms transform into solid rock. This replacement process results in the crystalline structure of dolomite.