Constituent
- Name
- Cristobalite
- IMA name
- alpha-Cristobalite
- Class
- silicate mineral
- Compound type
- tektosilicate
- Relevance
- main - major
- Arrangement
- single phase
- Mass fraction
- 1.0
- Formula
- $SiO_2$
- Chemical formula
- SiO2
- Elemental formula
- Si O2
- Isotope mixture type
- terrestrial abundance
- Oxides
-
Formula $SiO_{2}$ Mass fraction (%) 100.0
Strunz
- Class
- oxides - hydroxides - arsenites (04)
- Division
- metal:oxygen = 1:2 and similar (04.D)
- Family
- with small cations: Silica family (04.DA)
- Code
- 04.DA.15
Dana
- Major class
- silicates (VIII)
- Class
- tectosilicate Si tetrahedral frameworks (75)
- Type
- SiO2 with [4] coordinated Si (75.01)
- Group
- Cristobalite group (75.01.01)
- Code
- 75.01.01.01
- Phase name
- alpha-Cristobalite
- Phase type
- crystalline
- Crystal system
- tetragonal
- Crystal class
- trapezohedral
- Crystal class symbol
- 422 (D4)
- Crystal spacegroup
- P4(1)2(1)2
- Texture
- monocrystalline
- Molar mass
- 60.08 $g/mol$
- Density
- 2.32 - 2.36 $g/cm^3$
- Refringence type
- uniaxial
- Refringence sign
- negative
- Birefringence
- 0.003
- Refraction index $n_{\alpha}$
- 1.487
- Refraction index $n_{\beta}$
- 1.484
- Color
- colorless, white, blue gray, brown, gray, yellow
- Diaphaneity
- transparent to translucent
- Luster
- vitreous