Buff to tan colored almost brown biphosphammite crystals associated to white archerite from the type locality in Australia: Murra-el-elevyn Cave, Dundas Shire, Western Australia, Australia. — Photo: David Hospital · CC BY-SA 4.0
Biphosphammite
Biphosphammite is an IMA-recognized mineral species in the phosphate class, with the chemical formula (NH₄)H₂(PO₄).
It crystallizes in the tetragonal crystal system (space group I-42d). It is a member of the Biphosphammite structural group.
Key properties: specific gravity 2.04; White to pale buff streak; Dull, earthy; crystals rarely vitreous luster; optically uniaxial.
IMA symbol Bpam, grandfathered status — known before the IMA’s founding, named in 1870.
An alteration product of phosphammite in guano, due to loss of NH4 (Guañape Island, Peru); a byproduct of the reaction between the liquid fraction of bat guano and urea (Murra-el-elevyn Cave, Australia).
It is found associated with Phosphammite (Guañape Island, Peru); syngenite (Murra-el-elevyn Cave, Australia).
As a BIPHOSPHate of AMMonium.