avullin

Avullin is a rare, naturally occurring mineral. Its chemical formula is typically represented as Fe2+Fe3+2(PO4)2(OH)2, indicating it is an iron phosphate hydroxide. Avullin is known for its distinctive color, which can range from a deep purplish-red to a reddish-brown. It often forms in association with other phosphate minerals, particularly in pegmatites and hydrothermal veins.

The mineral's crystal structure is monoclinic, and it commonly appears as small, prismatic crystals or in fibrous aggregates. Avullin is relatively soft, with a Mohs hardness of around 4.5, and possesses a vitreous to greasy luster. Its specific gravity is typically in the range of 3.0 to 3.2.

Avullin was first discovered in the Ural Mountains of Russia. Since its initial identification, it has been found in scattered locations worldwide, including in parts of Africa and North America. Due to its rarity and the small size of its crystals, avullin is not a commercially significant mineral. However, it is of interest to mineralogists and collectors for its unique composition and aesthetic appeal. Further research continues to explore its geological occurrence and crystallographic properties.