Meaning

noun a kind of sedimentary rock resembling marble or limestone but rich in magnesium carbonate

noun a light colored mineral consisting of calcium magnesium carbonate; a source of magnesium; used as a ceramic and as fertilizer

originFrom French dolomite, coined March 1792 by Nicolas de Saussure, named after French mineralogist and engineer Déodat de Dolomieu (1750–1801) who described the stone in 1791 by adding -ite, from place name Dolomieu, Isère.

Etymology from Wiktionary, CC BY-SA 3.0