Dolomite is a carbonate sedimentary rock close to limestone
made up of more than 50% carbonates, at least half of which in the form of dolomite
. A distinction is usually made between primary dolomites, resulting from the direct precipitation of large quantities of dolomite in coastal lagoons, and secondary dolomites, resulting from a replacement by metasomatosis of the initial calcite
by dolomite (phenomenon of dolomitization).