Constituent
- Name
- Spinel
- IMA name
- Spinel
- Class
- non-silicate mineral
- Compound type
- oxide-hydroxide
- Relevance
- main - major
- Arrangement
- single phase
- Mass fraction
- 1.0
- Formula
- Mg$_{1.02}$Al$_{1.93}$Si$_{0.03}$Cr$_{0.0087}$Fe$_{0.012}$O$_{4}$
- Chemical formula
- Mg1.02 Al1.93 Si0.03 Cr0.0087 Fe0.012 O4
- Elemental formula
- (Mg)0-1 (Al)0-2 (O)0-4
- Isotope mixture type
- terrestrial abundance
- Composition comments
- The natural spinel sample has a minor OH content that is not shown in the formula of the chemical composition.
- Oxides
-
Formula $MgO$ $Al_{2}O_{3}$ $SiO_{2}$ $Cr_{2}O_{3}$ $Fe_{2}O_{3}$ Mass fraction (%) 23.45 74.81 0.51 0.5 0.72
Strunz
- Class
- oxides - hydroxides - arsenites (04)
- Division
- metal:oxygen = 3:4 and similar (04.B)
- Family
- with only medium-sized cations (04.BB)
- Code
- 04.BB.05
Dana
- Major class
- oxides and hydroxides (III)
- Class
- multiple oxides (07)
- Type
- (A+B++)2X4 Spinel group (07.02)
- Group
- Aluminium subgroup (07.02.01)
- Code
- 07.02.01.01
- Phase type
- crystalline
- Crystal system
- isometric (cubic)
- Crystal class
- hexoctahedral
- Crystal class symbol
- m-3m (Oh)
- Crystal spacegroup
- Fd-3m
- Molar mass
- 142.27 $g/mol$
- Density
- 3.57 - 3.72 $g/cm^3$
- Refringence type
- isotropic
- Refringence sign
- no
- Birefringence
- 0
- Refraction index $n_{\alpha}$
- 1.72 - 1.80
- Color
- dark-red
- Diaphaneity
- transparent to opaque
- Luster
- vitreous