Omphacite is a member of the clinopyroxene group of silicate minerals)(Mg 6. It is a variably deep to pale green or nearly colorless variety of clinopyroxene, which is the high-pressure metamorphic rock. Omphacite is the solid solution of Fe-bearing diopside It crystallizes in the monoclinic with prismatic, typically twinned forms, though usually anhedral. Its space group can be P2/n or C2/c depending on the thermal history. It exhibits the typical near 90° pyroxene cleavage. It is brittle with specific gravity of 3.29 to 3.39 and a Mohs hardness of 5 to 6.