Stellerite
Mineral CaAl2Si7O18·7H2O
About it
A calcium zeolite that looks like stilbite, in white to pinkish sheaves and blocky crystals in basalt and veins; telling them apart takes a lab test. Named for naturalist Georg Steller.
- Type
- Mineral
- Group
- Silicate (tectosilicate), zeolite group
- Formula
- CaAl2Si7O18·7H2O
- Hardness (Mohs)
- 3.5–5
- Specific gravity
- 2.1–2.2
- Streak
- white
- Lustre
- vitreous (glassy), pearly
- Crystal system
- Orthorhombic
- Colours
- colourless, white, pink, orange
- Transparency
- transparent, translucent
- Cleavage and fracture
- perfect in one direction
Typical values: real specimens vary. For more, see mindat.org.