Probertite
Mineral NaCaB5O7(OH)4·3H2O
About it
Colourless to white radiating sprays and nodules of prisms, found with ulexite at Boron, California, and in Turkey's borate deposits. Named for American mining engineer Frank Probert.
- Type
- Mineral
- Group
- Borate
- Formula
- NaCaB5O7(OH)4·3H2O
- Hardness (Mohs)
- 3.5
- Specific gravity
- 2.14
- Streak
- white
- Lustre
- vitreous (glassy), silky
- Crystal system
- Monoclinic
- Colours
- colourless, white
- Transparency
- transparent, translucent
- Cleavage and fracture
- perfect in one direction
Typical values: real specimens vary. For more, see mindat.org.