Struvite

Struvite (magnesium ammonium phosphate) is a phosphate mineral with formula: NH4MgPO4·6H2O. Struvite crystallizes in the orthorhombic system as white to yellowish or brownish-white pyramidal crystals or in platey mica-like forms. It is a soft mineral with Mohs hardness of 1.5 to 2 and has a low specific gravity of 1.7. It is sparingly soluble in neutral and alkaline conditions, but readily soluble in acid.Dog struvite bladder stonesStruvite crystals in a human urine sample with a pH of 9. Abundant amorphous phosphate crystals, several squamous and non-squamous epithelial cells and a few leukocytes can also be observed.Another image from the same urine sample as with the image on the left. Struvite (magnesium ammonium phosphate) is a phosphate mineral with formula: NH4MgPO4·6H2O. Struvite crystallizes in the orthorhombic system as white to yellowish or brownish-white pyramidal crystals or in platey mica-like forms. It is a soft mineral with Mohs hardness of 1.5 to 2 and has a low specific gravity of 1.7. It is sparingly soluble in neutral and alkaline conditions, but readily soluble in acid. Struvite urinary stones and crystals form readily in the urine of animals and humans that are infected with ammonia-producing organisms. They are potentiated by alkaline urine and high magnesium excretion (high magnesium/plant-based diets). They also are potentiated by a specific urinary protein, in domestic cats. Struvite was first described in 1845 by the German chemist Georg Ludwig Ulex  (1811–1883), who found crystals of struvite in what he surmised had once been a medieval midden in Hamburg, Germany ; he named the new mineral after the geographer and geologist Heinrich Christian Gottfried von Struve  (1772–1851) of Hamburg. Struvite is occasionally found in canned seafood, where its appearance is that of small glass slivers, objectionable to consumers for aesthetic reasons but of no health consequence. A simple test can differentiate struvite from glass.