Sedumit

Sedumit is a term that refers to a group of minerals containing the element selenium. While not a formal mineral group in the same way as silicates or carbonates, it is often used colloquially or in specific mineralogical contexts to describe selenium-bearing compounds. Selenium is a non-metal that can occur naturally in various minerals, often substituting for sulfur in sulfide minerals. Therefore, sedumit minerals are frequently found as rare telluride or sulfide species where selenium plays a significant role in their chemical structure.

Examples of minerals that could be considered sedumits include selenides, selenosulfides, and selenates. Selenides are compounds where selenium is bonded to a metal, such as clausthalite (PbSe). Selenosulfides are minerals where both selenium and sulfur are present, often in varying ratios, like pararammelsbergite (NiAs2). Selenates are salts containing the selenate anion (SeO4^2-). These minerals are typically found in hydrothermal veins and associated with other sulfide and telluride deposits. Due to their rarity and often complex chemical compositions, sedumit minerals are of interest to mineral collectors and geologists studying the distribution of selenium in the Earth's crust. Their occurrence is generally limited to specific geological environments.