SMITHSONITE (cabinet)

Smithsonite, or zinc spar, is the mineral form of zinc carbonate (ZnCO3). Initially, it was confused with hemimorphite due to their similar appearances, and both were referred to as calamine, which led to some misunderstandings. The mineral was officially named in 1832 by François Sulpice Beudant to honor the English scientist James Smithson, who first identified it in 1802. Smithsonite typically appears as earthy botryoidal masses rather than well-formed crystals and has a Mohs hardness of 4.5, with a specific gravity ranging from 4.4 to 4.5. It is primarily found as a secondary mineral in the weathering or oxidation zones of zinc-bearing ore deposits and can also form replacement bodies in carbonate rocks, contributing to zinc ore. Smithsonite is often associated with minerals such as hemimorphite, willemite, and malachite, and it can form limited solid solution series with manganese and iron, resulting in rhodochrosite and siderite, respectively. A notable bright yellow variety, sometimes referred to as "turkey fat ore," derives its color from greenockite inclusions within the crystals.