tilasitte

Tilasitte, also known as tilasite, is a rare mineral classified within the phosphate mineral group. Its chemical composition primarily consists of calcium and iron phosphates, often with the formula CaFe(PO4)2·2H2O. The mineral was first identified in the early 19th century and has since been recognized in various geological settings, particularly in phosphate-rich deposits.

Tilasitte typically forms through secondary mineralization processes in sedimentary environments. It is often associated with other phosphate minerals like apatite, variscite, and wavellite. Its crystal structure generally appears in prismatic or tabular forms, with a vitreous to resinous luster. The mineral's color can vary from green to bluish-green, often attributed to its iron content.

The mineral’s physical properties include a Mohs hardness of about 3.5 to 4 and a specific gravity ranging between 2.9 and 3.1. It is relatively soluble in weak acids, which aids in its identification in the field. Tilasitte is of interest primarily to mineral collectors and geologists due to its rarity and distinctive appearance.

Despite its limited occurrence, tilasitte provides valuable insights into the mineralogical processes occurring in phosphate-rich geological environments. It also contributes to the understanding of secondary mineral formation and the geochemical cycling of phosphorus within the Earth's crust. However, tilasitte does not have significant industrial applications owing to its scarcity. Its primary significance lies in its role for scientific study and mineralogical documentation.