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}
Fractureconchoidal
Specific Gravity2.11
Colorswhite, colorless, gray, yellowish
Transparencytransparent
Type LocalityWorldwide in arid regions, caves, and as efflorescence; historically significant deposits in Chile and India.
Mineral GroupNitrates
Usesfertilizer, gunpowder, food preservation, pyrotechnics
Associated Mineralsnitrocalcite, nitratine, gypsum, halite
Rarityuncommon
Description
The image shows a dense growth of delicate, needle-like to fibrous, translucent white crystals forming an efflorescence on a yellowish-green substrate. These crystals appear to be growing upwards from the surface, creating a feathery or brush-like texture.
Geological Context
Niter typically forms as an evaporite mineral in arid environments, often as efflorescence on cave walls, in soils, or on rocks where organic matter decomposition provides nitrogen and potassium is available from the host rock. It is a secondary mineral formed under specific dry conditions.
