Violarite

Violarite is a rare sulfide mineral with the chemical formula FeNi2S4. It is an end-member of the violarite group and is typically found in hydrothermal deposits and altered mafic and ultramafic rocks. It is known for its characteristic steel-gray to pale violet color, which gives it its name. Violarite forms in low-temperature environments and is often associated with millerite and pentlandite.

This mineral is a secondary mineral, meaning it forms from the alteration of pre-existing minerals. It is commonly found as a weathering product of pentlandite, a primary nickel sulfide. The formation of violarite is facilitated by the presence of oxidizing agents and water. Its occurrence is relatively limited, making it a mineral of interest to geologists and mineral collectors.

Crystallographically, violarite belongs to the tetragonal crystal system. It typically appears as massive aggregates, granular masses, or small disseminated crystals. While not economically significant as a primary ore of nickel due to its rarity, it can be a component of nickel sulfide deposits. Its presence can indicate specific geological conditions related to ore formation and alteration processes.