smithsonitt

Smithsonitt is not a recognized mineral name in major mineralogical references. The spelling appears to be a nonstandard or erroneous variant of smithsonite, the well-known zinc carbonate mineral ZnCO3. When encountered in literature, smithsonitt most often refers to smithsonite in error or as a typographical variant, and serious scientific discussion uses the standard name smithsonite.

Smithsonite is a secondary zinc carbonate mineral forming in the oxidized zones of zinc ore deposits. It crystallizes in the trigonal (often described as hexagonal) system and commonly occurs as botryoidal, mamillated, or crust-like aggregates; well-formed crystals are rare. Colors range widely from colorless to greens, blues, pinks, yellows, and browns, imparted by impurities such as manganese, cobalt, nickel, iron, or copper. The mineral has a vitreous to pearly luster and a Mohs hardness around 4.5. It readily effervesces with dilute acids, reflecting its carbonate composition.

Etymology and naming: smithsonite is named in honor of James Smithson (c. 1765–1829), a British scientist who founded the Smithsonian Institution in the United States.

Occurrence and locality: smithsonite occurs worldwide, with notable deposits in Mexico (Ojuela Mine), Namibia (Tsumeb), Australia, and Europe. It is commonly associated with other secondary minerals such as hydrozincite, cerussite, and hemimorphite. Because of its attractive color variety, smithsonite is highly prized by mineral collectors, and it is sometimes mined as a zinc ore in oxidized zones, though it is not a primary zinc ore in most mining operations.