Tunellite
Mineral SrB6O9(OH)2·3H2O
About it
Colourless, platy to prismatic crystals of strontium borate with one perfect cleavage, from Boron, California, and Turkey. Named for American geologist George Tunell.
- Type
- Mineral
- Group
- Borate
- Formula
- SrB6O9(OH)2·3H2O
- Hardness (Mohs)
- 2.5
- Specific gravity
- 2.4
- Streak
- white
- Lustre
- vitreous (glassy), pearly
- Crystal system
- Monoclinic
- Colours
- colourless
- Transparency
- transparent, translucent
- Cleavage and fracture
- perfect in one direction
- Under UV light
- yellow under UV
Typical values: real specimens vary. For more, see mindat.org.