Borax
Mineral Na2B4O5(OH)4·8H2O
Also called Tincal
Take care.
- Damaged by water: Keep it dry: don't wash it, and keep it out of damp places.
About it
Colourless, stubby prisms from dry lake beds that turn chalky white as they lose water in dry air (becoming tincalconite) unless sealed. Big crystals come from Boron and Searles Lake, California.
- Type
- Mineral
- Group
- Borate
- Formula
- Na2B4O5(OH)4·8H2O
- Hardness (Mohs)
- 2–2.5
- Specific gravity
- 1.71–1.72
- Streak
- white
- Lustre
- vitreous (glassy), resinous, earthy
- Crystal system
- Monoclinic
- Colours
- colourless, white, grey, pale yellow, pale blue
- Transparency
- transparent, translucent
- Cleavage and fracture
- perfect in one direction; conchoidal fracture
Typical values: real specimens vary. For more, see mindat.org.