Struviitti

Struviitti is a mineral that belongs to the phosphate group. Its chemical formula is magnesium ammonium phosphate hexahydrate, with the formula MgNH4PO4·6H2O. Struviitti is named after Gustav von Struve, a German chemist. It commonly forms in specific environments, most notably as a precipitate in urine, where it is known as a type of urinary calculus or stone. These stones form when urine becomes supersaturated with magnesium, ammonium, and phosphate ions. Factors that can contribute to struviitti stone formation include urinary tract infections, particularly those caused by urease-producing bacteria that increase urine pH, and certain metabolic conditions.

In addition to its occurrence in biological systems, struviitti can also be found in guano deposits and as a rare mineral in some geological settings. It typically appears as colorless to white or yellowish prismatic crystals. Struviitti is relatively soft and has a Mohs hardness of 1.5 to 2.0. It is soluble in acids. While often considered a nuisance in the context of human health due to its formation as kidney or bladder stones, struviitti has also been explored for its potential as a fertilizer, as it contains essential nutrients like nitrogen and phosphorus. The recovery of struviitti from wastewater is an area of research aimed at resource recovery and pollution control.