Making It and Using It

Calamine was mined as an earthy, often yellowish or brownish mineral found in the weathered upper zones of zinc-bearing ore deposits, and its principal use for well over a thousand years was in brassmaking: crushed calamine was smelted together with copper ore or metallic copper in a closed crucible, the zinc content vaporizing at the smelting temperature and alloying directly into the molten copper before it could escape, producing brass without the maker ever seeing, isolating or even necessarily suspecting the existence of a separate zinc metal. This calamine brass process, called cementation, was the dominant method of brass production across much of the ancient and medieval world, and it worked reliably as a craft technique for far longer than anyone could have explained why it worked in terms of a distinct third metal being incorporated.

Calamine also found use in medicine, ground and prepared as a mild astringent and soothing application for skin complaints, a use that persists today under the same name in commercial calamine lotion, though the modern pharmaceutical formulation is a defined mixture of zinc oxide and a small amount of iron oxide rather than the historical mined mineral itself. The historical material sold as calamine was not chemically uniform, since different deposits yielded ore of somewhat different mineral composition, all grouped under the one practical trade name because they behaved similarly in the brassmaking furnace regardless of their precise underlying chemistry.