Celsian
Mineral BaAl2Si2O8
About it
Barium feldspar, much heavier in the hand than orthoclase, found in manganese and barium deposits; named for Anders Celsius, with its type locality at Jakobsberg, Sweden.
- Type
- Mineral
- Group
- Silicate (tectosilicate), feldspar group
- Formula
- BaAl2Si2O8
- Hardness (Mohs)
- 6–6.5
- Specific gravity
- 3.1–3.39
- Streak
- white
- Lustre
- vitreous (glassy)
- Crystal system
- Monoclinic
- Colours
- colourless, white, yellow
- Transparency
- transparent, translucent
- Cleavage and fracture
- perfect and good in two directions
Typical values: real specimens vary. For more, see mindat.org.