Dolomite

Dolomite ( /ˈdɒləmaɪt/) is a carbonate mineral composed of calcium magnesium carbonate CaMg(CO3)2. The term is also used to describe the sedimentary carbonate rock dolostone.

Dolostone (dolomite rock) is composed predominantly of the mineral dolomite with a stoichiometric ratio of 50% or greater content of magnesium replacing calcium, often as a result of diagenesis. Limestone that is partially replaced by dolomite is referred to as dolomitic limestone, or in old U.S. geologic literature as magnesian limestone.

Read more about Dolomite:  History, Properties, Formation, Uses