Ferrotychite is a rare mineral of complex composition and belongs to the tyrolite group. It is typically found in oxidized copper deposits, specifically associated with secondary copper minerals. The mineral is named "ferrotychite" due to its iron content, which is a distinguishing feature.
Chemically, ferrotychite is described as a hydrated copper iron arsenate sulfide. Its chemical formula is Cu2Fe3+(AsO4)2(OH)2•6H2O. This composition indicates that it consists of copper (Cu), iron (Fe), arsenate (AsO4), hydroxide (OH), and water (H2O). The presence of these elements and compounds contributes to its characteristic properties.
Physically, ferrotychite is typically found as bladed or acicular crystals, often forming fibrous aggregates. The mineral can exhibit a range of colors, including yellowish-green, green, brownish-green, or blackish-green. It has a vitreous to silky luster, and its streak is light green. Ferrotychite has a relatively low hardness, ranging from 2 to 3 on the Mohs scale.
The occurrence of ferrotychite is relatively rare, and it is primarily found in specific localities around the world. Its known occurrences include the Tsumeb mine in Namibia, Broken Hill in Australia, and the Långban mine in Sweden. These localities are known for their rich copper and mineral deposits.
Ferrotychite is of interest to mineral collectors due to its rarity and distinctive crystal forms. Its unique chemical composition also makes it a subject of research in the field of mineralogy and mineral chemistry.
