augelite

Augelite is a rare phosphate mineral with the chemical formula Al2(PO4) F. It crystallizes in the monoclinic system and typically forms small, prismatic crystals. Augelite is known for its hardness, ranking between 4.5 and 5 on the Mohs scale, and its vitreous luster. Pure augelite is colorless or white, but impurities can lead to various colors, including yellow, pale blue, and greenish. It is often found in pegmatites and metamorphic rocks, frequently associated with other phosphate minerals like apatite and lazulite. Notable occurrences of augelite have been reported in Sweden, Brazil, and the United States. While not a gem-quality mineral due to its rarity and tendency to be found in small crystals, augelite is of interest to mineral collectors and geologists for its unique chemical composition and crystal structure. Its name is derived from the Greek word "augetes," meaning "augmenter," likely referring to its association with ore bodies.