Creedite
Mineral Ca3Al2(SO4)(F,OH)10·2H2O
About it
Radiating sprays of colourless, purple, or orange prisms, often with fluorite. Named for Creede, Colorado; fine sprays come from Santa Eulalia, Mexico, and Akchatau, Kazakhstan.
- Type
- Mineral
- Group
- Halide
- Formula
- Ca3Al2(SO4)(F,OH)10·2H2O
- Hardness (Mohs)
- 3.5–4
- Specific gravity
- 2.71–2.73
- Streak
- white
- Lustre
- vitreous (glassy)
- Crystal system
- Monoclinic
- Colours
- colourless, white, purple, orange
- Transparency
- transparent, translucent
- Cleavage and fracture
- perfect in one direction
Typical values: real specimens vary. For more, see mindat.org.