Mineralpedia Details for Pentahydroborite
Pentahydroborite
Name is actually a misnomer for the composition which was originally described as having five (penta) water molecules per each formula unit. A rare mineral found only in Russia, Serbia, Japan, and possibly Kazakhstan. Pentahydoborite occurs as a mineral in boron bearing iron ore skarn and in volcanogenic sedimentary borate deposits. Pentahudroborite will fluoresce a purple-violet color under long-wave ultraviolet light.
Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/pentahydroborite.pdf
- Formula
- CaB2O(OH)6ยท2H2O
- Crystal System
- Triclinic
- Crystal Habit
- Granular
- Cleavage
- None, None, None
- Luster
- Vitreous (Glassy)
- Color
- colorless
- Streak
- white
- Class
- Triclinic - Pinacoidal
- Hardness
- 2.5
- WebMineral
- View Pentahydroborite
- Mindat
- View Pentahydroborite
Pentahydroborite from Fuka mine, Bitchu-cho, Okayama pref., Honsuh Island, Japan
Brown crystalline in matrix.
Click thumbnail images for larger view.
