Cassiterite

Mined since the Bronze Age, cassiterite is the principal ore of tin, a tin oxide (SnO2) that crystallizes in the tetragonal system. It forms in high-temperature hydrothermal veins and concentrates in placer deposits, with major sources in China, Indonesia, and Malaysia. The mineral shows an adamantine luster, a white to pale-brown streak, and poor {100} cleavage, appearing in prismatic, bipyramidal, or botryoidal forms. Its brown to black colors and notably high specific gravity of 6.80 to 7.10 aid identification, and its Mohs hardness ranges from 6 to 7. Cassiterite remains the dominant economic source of tin worldwide. Its adamantine luster and great weight help separate it from the darker oxides with which it is sometimes confused.

Cassiterite is the principal ore of tin and has been mined since the Bronze Age. It occurs primarily in high-temperature hydrothermal veins and placer deposits. Major sources include China, Indonesia, and Malaysia.