duffesith

Duffesith, also known as duffesite, is a rare, naturally occurring mineral with the chemical formula (NH4)2Fe(SO4)2·6H2O. It was first discovered in 1976 in the Cap Garonne mine in France, and its name is derived from the French word "duffe," meaning "foolish," in reference to the mineral's unusual and complex crystal structure. Duffesith is typically found in the form of small, prismatic crystals or as encrustations on other minerals. It is often associated with other sulfate minerals such as alunite and jarosite. The mineral is characterized by its bright yellow to orange color, which is due to the presence of iron in its chemical composition. Duffesith is relatively soft, with a Mohs hardness of 2.5 to 3, and has a specific gravity of approximately 1.9. It is soluble in water and can form efflorescent crusts in arid environments. Due to its rarity and unique properties, duffesith is of interest to mineral collectors and researchers studying the geochemistry of sulfate minerals.