Sturmanite

This thumbnail specimen features a sharp, sturmanite crystal, displaying the mineral’s characteristic opaque beige-brown tones that impart a warm, earthy glow. The crystal shows well-defined edges and excellent form, making it an attractive example of this rare and unusual mineral. Sturmanite, a calcium–manganese–iron–sulfate–borate carbonate, is known almost exclusively from the Kalahari Manganese Field in South Africa, with the Wessels Mine being a classic locality. This fine piece comes from the collection of Robert Yeoman, an Irish-born collector based in Toronto, whose collection is especially noted for minerals from classic localities worldwide.