magnesite

A white, yellowish, or brown mineral, magnesium carbonate, MgCO₃, used in the manufacture of magnesium oxide and carbon dioxide.

Native magnesium carbonate, a mineral occurring in white compact masses, less often in rhombohedral crystals. It belongs to the calcite group.

the hydrated magnesium silicate usually called sepiolite or meerschaum.

Native magnesium carbonate occurring in white compact or granular masses, and also in rhombohedral crystals.

A form of magnesium carbonate, MgCO3, occurring as dolomite (with calcite) but rarely found in the pure state.

a white mineral consisting of magnesium carbonate; a source of magnesium