struvite

{{Infobox mineral | name = Struvite | category = Phosphate mineral | boxwidth = | boxbgcolor = | image = Struvite crystals dog with scale 1.JPG | imagesize = | caption = Crystals of struvite from dog urine | formula = | IMAsymbol = Suv | molweight = | strunz = 8.CH.40 | system = Orthorhombic | class = Pyramidal (mm2) H-M symbol: (mm2) | symmetry = Pmn21 | color = Colorless, white (dehydrated), yellow or brownish, light gray | habit = Euhedral to platy | twinning = On {001} | cleavage = {100} perfect | fracture = Uneven | mohs = 1.5–2 | luster = Vitreous to dull | refractive = nα = 1.495 nβ = 1.496 nγ = 1.504 | opticalprop = Biaxial (+) 2V Measured: 37° | birefringence = δ = 0.009 | pleochroism = | streak = White | gravity = 1.7 | density = | melt = | fusibility = | diagnostic = | solubility = Slightly soluble, dehydrates in dry, warm air | diaphaneity = Transparent to translucent | other = Pyroelectric and piezoelectric | references = }}

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 platy 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.