a white mineral often tinted by impurities, found in sedimentary rocks and veins. It is used in the manufacture of cement and as a building stone (marble). Composition: calcium magnesium carbonate. Formula: CaMg(CO3)2. Crystal structure: hexagonal (rhombohedral)
2.
a sedimentary rock resembling limestone but consisting principally of the mineral dolomite. It is an important source of magnesium and its compounds, and is used as a building material and refractory
[C18: named after Déodat de Dolomieu (1750--1801), French mineralogist]