Humboldtin

Humboldtin is a rare, naturally occurring mineral with the chemical formula (Fe,Mg)3Al2(SiO4)3. It was first discovered in 1845 in the Humboldt Mine in the Clark County, Nevada, United States, and is named after the mine. Humboldtin is a member of the humboldtine group, which also includes the minerals humboldtite and magnesiohumboldtine. The mineral is typically found in skarn deposits, which are contact metamorphic rocks formed when magma intrudes into carbonate rocks. Humboldtin crystals are usually small, ranging from a few millimeters to a centimeter in size, and are typically dark green to black in color. The mineral has a hardness of 6.5 to 7 on the Mohs scale and a specific gravity of approximately 3.5 to 3.6. Humboldtin is not commonly used in industry due to its rarity and the difficulty in extracting it from its host rocks. However, it is of interest to mineral collectors and researchers studying the geology of skarn deposits.