Quick Reference

Mineral, SnO2; sp. gr. 6.8–7.1; hardness 6–7; tetragonal; usually reddish-brown to nearly black, but it can be yellowish and ruby; white to grey streak; adamantine lustre; crystals often pyramidal and prismatic, may also be massive and granular; cleavage prismatic {100}, {110}; occurs typically in high-temperature hydrothermal veins, with granites and pegmatites; associated minerals: topaz, quartz, tourmaline, mica, chlorite, and high-temperature metallic ores; also world-wide in alluvial deposits because of its resistance to chemical and physical attack. Cassiterite is the only important ore for tin.

Subjects: Earth Sciences and Geography.

Reference entries