Gwihabaite
A rare ammonium-potassium nitrate found in Botswana's caves — colorless, orthorhombic, hardness 5.
Intro adapted from Wikipedia (CC BY-SA).
Gwihabaite is an IMA-recognized mineral species in the nitrate class, with the chemical formula (NH₄)(NO₃).
It crystallizes in the orthorhombic crystal system (space group Pbnm).
Key properties: Mohs hardness 2; specific gravity 1.77; White streak; Vitreous luster; optically biaxial.
IMA symbol Gwi, IMA status: approved, named in 1994.
Occurs as crusts and efflorescences formed by bacterial action on bat guano in caves.
It is found associated with Gypsum, syngenite, boussingaultite, dittmarite, weddellite, glushinskite, struvite, biphosphammite (Gcwihaba Cave, Botswana) struvite.
The name refers to Gcwihaba Cave where the first specimens were collected.