molybdenite Mineral, MoS₂; sp. gr. 4.6–4.8; hardness 1.0–1.5; hexagonal; pale bluish to lead-grey; greenish-grey streak; metallic lustre; crystals hexagonal, often tabular grains, and it also occurs as foliated and scaly masses; cleavage perfect basal hexagonal; quite widespread but seldom occurs in large quantities, found as an accessory mineral in granites, quartz veins, and pegmatites, in contact metamorphic zones with garnets, pyroxenes, scheelite, pyrite, and tourmaline, and in veins with scheelite, wolframite, cassiterite, and fluorite. It is a major ore mineral for molybdenum.

molybdenite (molybdenum sulphide, MoS₂) Sulphide mineral, found in pegmatites, igneous and metamorphic rocks. It is a major ore of molybdenum. It has hexagonal system tabular prisms, flakes, and fine granules. It is lead-grey in colour with a metallic lustre. Hardness 1–1.5; r.d. 4.7.