Tincalconite
Mineral Na2B4O5(OH)4·3H2O
Take care.
- Damaged by water: Keep it dry: don't wash it, and keep it out of damp places.
About it
Chalky white powder and pseudomorphs that form as borax loses water; the white coating on most old borax specimens is tincalconite. Natural crystals are rare; found at Boron and Searles Lake, California.
- Type
- Mineral
- Group
- Borate
- Formula
- Na2B4O5(OH)4·3H2O
- Hardness (Mohs)
- 2
- Specific gravity
- 1.88
- Streak
- white
- Lustre
- vitreous (glassy), dull, earthy
- Crystal system
- Trigonal
- Colours
- white, colourless
- Transparency
- translucent, opaque
- Cleavage and fracture
- none
Typical values: real specimens vary. For more, see mindat.org.