Niter
Mineral KNO3
Also called Saltpetre and Nitre
Take care.
- Damaged by water: Keep it dry: don't wash it, and keep it out of damp places.
About it
White fluffy crusts and needles on cave walls, soils, and old masonry that dissolve easily in water. Long scraped from caves to make gunpowder; it is the mineral form of saltpetre.
- Type
- Mineral
- Group
- Nitrate
- Formula
- KNO3
- Hardness (Mohs)
- 2
- Specific gravity
- 2.09–2.11
- Streak
- white
- Lustre
- vitreous (glassy), silky
- Crystal system
- Orthorhombic
- Colours
- white, colourless, grey
- Transparency
- transparent, translucent
- Cleavage and fracture
- good in one direction
Typical values: real specimens vary. For more, see mindat.org.