Dolomite

Dolomite is a calcium magnesium carbonate mineral which has many characteristics similar to calcite. In places where access to limestone is not available or more costly, dolomites are used in its place for the basic materials from which most building stone and a significant percentage of crushed stone are produced.

Most rocks that are rich in dolomite were originally deposited as calcium carbonate muds that were post depositionally altered by magnesium-rich pore water to form dolomite.