Dol"o*mite (d&obreve;l"&osl;*mīt), n. [After the French geologist Dolomieu.] (Geol. & Min.) A mineral consisting of the carbonate of lime and magnesia in varying proportions. It occurs in distinct crystals, and in extensive beds as a compact limestone, often crystalline granular, either white or clouded. It includes much of the common white marble. Also called bitter spar.