Witherite

Witherite is a mineral consisting of barium carbonate (BaCO3). It is a relatively rare carbonate and crystallizes in the orthorhombic system, forming prismatic to tabular crystals as well as granular masses. The color is typically colorless to white, often with pale yellow or gray tints; crystals are transparent to translucent and have a vitreous luster. On the Mohs scale, its hardness is about 3.5, and its specific gravity is around 4.3.

Witherite forms in hydrothermal veins within carbonate rocks and is commonly found alongside minerals such as fluorite, calcite, barite, and sphalerite. It is associated with alteration zones in limestone and dolostone and can occur in both vein and replacement deposits.

Notable localities include North Wales in the United Kingdom, as well as deposits in Germany and the Czech Republic. Additional occurrences have been reported in North America and other regions, though the mineral remains relatively uncommon on a global scale.

Economically, witherite is a minor source of barium. The BaCO3 produced from witherite can be processed to other barium compounds used in glassmaking, ceramics, and various chemical applications, but it is not as commercially important as barite (BaSO4), which is more abundant as a source of barium.