A representative collection (138 analyses) of chromites from kimberlites of the Botuobinskaya pipe in Yakutia was studied. With allowance for the Cr, Ti, and Al contents, the chromites are subdivided into the low Cr aluminous group A and the high Cr and high Ti group B. The chromites of group A with their compositional variations controlled by the Al 3+ -Cr 3+ isomorphism are not related to kimberlite in compo sition and reveal attributes of restites. The chromites of group B with heterovalent Ti 4+ + Fe 2+ + Fe 3+ -3Cr 3+ isomorphism vary in their composition in line with the compositional variations of kimberlites, thus demon strating their primary magmatic origin. The chromites of the second group crystallized simultaneously with olivines from kimberlites, and both minerals could have formed nodules of spinel dunite.
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