Black tin

Black tin is the raw ore of tin, usually cassiterite, as sold by a tin mine to a smelting company. After mining, the ore has to be concentrated by a number of processes to reduce the amount of gangue it contains before it can be sold. It contrasts with white tin, which is the refined, metallic tin produced after smelting.

A lump of "black tin", so called because of its color; in this case it is cassiterite from Cornwall

The term "black tin" was historically associated with tin mining in Devon and Cornwall.

References

• Chambers's encyclopædia: A dictionary of universal knowledge. 1868. p. 448.
• Blanchard, Ian (2005). Mining, Metallurgy, and Minting in the Middle Ages: Continuing Afro-European Supremacy, 1250-1450. p. 1526. ISBN 9783515087049.
• Carew, Richard (1811). Carew's Survey of Cornwall: To which are added, notes illustrative of its history and antiquities. p. 40.
• Rickard, William (1859). The miner's manual of arithmetic and surveying ...: With a compendium of mensuration and a concise treatise on practical geometry and plane trigonometry; also a course of mine surveying ... Together with levelling and land surveying. p. 38.