cassiterite kəsĭt´ərīt [key], heavy, brown-to-black mineral, tin oxide, SnO2, crystallizing in the tetragonal system. It is found as short prismatic crystals and as irregular masses, usually in veins and replacement deposits associated with granites. Since it is hard, heavy, and resistant to weathering, it often concentrates in alluvial deposits derived from cassiterite-bearing rocks. It is the principal ore of tin and is mined in many countries; the most important sources are Malaysia, Thailand, China, Indonesia, Bolivia, and Russia. Except for Bolivia, nearly all of this production is from alluvial deposits.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2023, Columbia University Press. All rights reserved.
See more Encyclopedia articles on: Mineralogy and Crystallography