hidarite

Hidarite is a rare mineral composed primarily of iron and arsenic, with the chemical formula FeAs. It is a member of the arsenide group of minerals and is known for its metallic luster and pale brass-yellow to steel-gray color. Hidarite crystallizes in the orthorhombic crystal system. It is typically found in hydrothermal veins and in association with other arsenic-bearing minerals. The mineral is relatively soft, with a Mohs hardness of around 3.5, and has a high specific gravity.

The discovery of hidarite is attributed to I. S. Hidari, after whom the mineral is named. It has been found in several locations worldwide, including in Sweden, the United States, and China, though deposits are generally small and not commercially significant for mining. Due to its rarity and the presence of arsenic, hidarite is not widely used in industrial applications. It is of interest primarily to mineral collectors and geologists studying mineral formation and composition. The presence of arsenic makes it a toxic mineral, and appropriate handling precautions are necessary. Further research into its properties and geological occurrences continues to be an area of interest within mineralogy.