Niter (Salpetre)
Image: <bdi><a href="//commons.wikimedia.org/wiki/User:ComputerHotline" title="User:ComputerHotline">Thomas Bresson</a></bdi> (CC BY 3.0)
Mineral NameNiter (Salpetre)
Chemical FormulaKNO₃
Mohs Hardness2
Crystal Systemorthorhombic
Lustervitreous
Streak Colorwhite
Cleavageperfect on {011}, distinct on {110}
Fractureuneven
Specific Gravity2.11
Colorswhite, colorless, gray, yellowish
Transparencytransparent
Type LocalityWorldwide in arid regions, caves, and as efflorescence
Mineral GroupNitrates
Usesfertilizer, gunpowder (historical), food preservation (historical)
Associated Mineralscalcite, gypsum, other evaporite minerals
Rarityuncommon
Description
The image shows delicate, hair-like or fibrous crystals of a white to very pale yellowish mineral, growing as an efflorescence on a yellowish substrate.
Geological Context
Niter forms as an evaporite mineral, typically as efflorescence on cave walls, in arid soils, or in areas with decaying organic matter and animal waste, where nitrogenous compounds are oxidized to nitrates.
