Cristobalite
Mineral SiO2
About it
A high-temperature form of silica in tiny white spheres and octahedra lining cavities in volcanic rock; the white "snowflakes" in snowflake obsidian are cristobalite.
- Type
- Mineral
- Group
- Silicate (tectosilicate), silica group
- Formula
- SiO2
- Hardness (Mohs)
- 6–7
- Specific gravity
- 2.32–2.36
- Streak
- white
- Lustre
- vitreous (glassy)
- Crystal system
- Tetragonal
- Colours
- white, colourless, grey, bluish
- Transparency
- transparent, translucent
- Cleavage and fracture
- none; uneven to conchoidal fracture
Typical values: real specimens vary. For more, see mindat.org.