Mineral phase
IMA name
Magnetite
Type
Class
non-silicate mineral
Compound type
oxide-hydroxide
Comments
Equivalent Space Group: Fd3m (227)
Chemical composition
Formula
$Fe^{2+}\!Fe^{3+}_2\!O_4$
Chemical formula
(Fe2+)(Fe3+)2O4
Elemental formula
(Fe2+) (Fe3+)2 O4
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Fe^{2+}$ Iron(II) cation element 1 constituent element main
$Fe^{3+}$ Iron(III) cation element 2 constituent element main
$O$ Oxygen element 4 constituent element main
Composition comments
common impurities: Ti, Mg, Zn, Mn, Ni, Cr, V, Al
Oxides
Formula $FeO$ $Fe_{2}O_{3}$
Mass fraction (%) 31.03 68.97

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
Iron subgroup (07.02.02)
Code
07.02.02.03
Phase type
crystalline
Crystal system
isometric (cubic)
Crystal class
hexoctahedral
Crystal class symbol
m-3m (Oh)
Crystal spacegroup
Fd-3m
Molar mass
231.54 $g/mol$
Density
5.1 - 5.2 $g/cm^3$
State NTP
solid
Refringence type
isotropic
Refringence sign
no
Birefringence
0
Refraction index $n_{\alpha}$
2.42
Pure color
black
Color
grayish black, iron black
Diaphaneity
opaque
Luster
metallic
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