Mineral phase
IMA name
Hematite
Secondary names
Specularite
Type
Class
non-silicate mineral
Compound type
oxide-hydroxide
Chemical composition
Formula
$Fe_2O_3$
Chemical formula
Fe2O3
Elemental formula
(Fe3+)2 O3
Isotope mixture type
terrestrial abundance
  Formula Name Family Number min-max Isotope mole fraction State Relevance
$Fe^{3+}$ Iron(III) cation element 2 constituent element main
$O$ Oxygen element 3 constituent element main
Composition comments
Common impurities: ?
Oxides
Formula $Fe_{2}O_{3}$
Mass fraction (%) 100.0

Strunz

Class
oxides - hydroxides - arsenites (04)
Division
metal:oxygen = 2:3, 3:5, and similar (04.C)
Family
with medium-sized cations (04.CB)
Code
04.CB.05

Dana

Major class
oxides and hydroxides (III)
Class
simple oxides (04)
Type
with a cation charge of 3+ (A+++2O3) (04.03)
Group
Corundum-Hematite group (Rhombohedral: R-3c) (04.03.01)
Code
04.03.01.02
Phase type
crystalline
Crystal system
trigonal
Crystal class
ditrigonal-scalenohedral
Crystal class symbol
-3m (D3d)
Crystal spacegroup
R-3c
Crystal sites
Label Nb Type Wp Specie Specie coordinence Specie occupancy Specie oxidation state
Fe 2 main  $Fe$ tetrahedral IV 1.0
O 3 main  $O$ 1.0
Molar mass
159.69 $g/mol$
Density
5.3 $g/cm^3$
State NTP
solid
Refringence type
uniaxial
Refringence sign
negative
Birefringence
0.280
Refraction index $n_o$ (w)
3.15 - 3.22
Refraction index $n_e$ (e)
2.87 - 2.94
Pure color
black
Color
reddish gray, black, blackish red
Diaphaneity
subtranslucent to opaque
Luster
metallic
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