TradeVerify Color Iron-black; gray with a brownish tint in reflected lightCrystal habit Granular to massive and lamellar exsolutions in hematite or magnetiteCrystal system TrigonalTwinning {0001} simple, {1011} lamellarCleavage absent; parting on {0001} and {1011}Fracture Conchoidal to subconchoidalTenacity BrittleMohs scale hardness 5?6Luster Metallic to submetallicStreak BlackDiaphaneity OpaqueSpecific gravity 4.70?4.79Optical properties Uniaxial (?)Birefringence Strong; O = pinkish brown, E = dark brown (bireflectance)Other characteristics weakly magnetic