Outstanding plenty of white crystals of the extremely rare ammonium Mn phosphate mineral niahite from the famous Sterling Hill mine (Sterling Mine, Ogdensburg, Sussex County, New Jersey, United States of America) and one of the only three known localities worlwide, and associated to witherite after the label. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY 4.0
Niahite
Niahite is an IMA-recognized mineral species in the phosphate class, with the chemical formula (NH₄)Mn²⁺(PO₄)·H₂O.
It crystallizes in the orthorhombic crystal system (space group Pmn2_1).
Key properties: specific gravity 2.39; White streak; optically biaxial.
IMA symbol Nhi, IMA status: approved, named in 1977.
A rare mineral, derived from the breakdown of bat guano (Niah Great Cave, Sarawak, Malaysia).
It is found associated with Newberyite, collophane, hannayite, struvite, variscite (Niah Great Cave, Sarawak, Malaysia); newberyite, sussexite, pyrochroite (Sterling Hill, New Jersey, USA).
The name refers to the place of its first-noted occurrence, the Niah Great Cave, Malaysia.