Belloite

Belloite is a rare copper tellurite mineral with the chemical formula Cu(TeO₃). It is a secondary mineral formed by the oxidation of tellurides in copper deposits. Typically, belloite is found as microscopic to small prismatic or tabular crystals, often associated with other tellurium minerals like emmonsite, blakeite, and tenorite.

Belloite crystals are typically light green to yellowish-green in color. They possess a vitreous luster and are translucent to transparent. The mineral exhibits a Mohs hardness of approximately 3.5 and a specific gravity of around 4.7.

The name "belloite" honors Frank Bello, a mineral collector who discovered the mineral at the Centennial Eureka Mine in Juab County, Utah, USA. This mine is considered the type locality for belloite. While first discovered in Utah, belloite has also been found in other locations, including various occurrences worldwide where tellurium-rich copper deposits are present. Due to its rarity and small crystal size, belloite is primarily of interest to mineral collectors and researchers studying tellurium mineralization.