Jeremejevite
Mineral Al6(BO3)5F3
About it
Pale blue to colourless six-sided prisms, rare and prized as crystals and gems. Namibia's Erongo Mountains give the best crystals; it was first found in Siberia and named for Russian mineralogist Pavel Jeremejev.
- Type
- Mineral
- Group
- Borate
- Formula
- Al6(BO3)5F3
- Hardness (Mohs)
- 6.5–7.5
- Specific gravity
- 3.28–3.31
- Streak
- white
- Lustre
- vitreous (glassy)
- Crystal system
- Hexagonal
- Colours
- colourless, pale blue, pale yellow, light brown
- Transparency
- transparent, translucent
- Cleavage and fracture
- none; conchoidal fracture
Typical values: real specimens vary. For more, see mindat.org.