Iron Oxide Hematite type
Fe2O3
Chemical name
Iron Oxide Hematite type
Mineral name
Hematite
Chemical formula
Fe2O3
Melting point [°C]
1539 - 1569
Crystal system
trigonal
Crystal Class
ditrigonal-scalenohedral (-3 2/m)
Space Group
R-3c
Unit cell
a [Å]:5.04
b [Å]:5.04
c [Å]:13.77
Molecular weight [g/mol]
159,70
Formula units
Z=6
Frequent crystal surfaces
{10-11}, {10-12}, {0001}, {10-18}, {11-23}, {01-14}, {01-11}, {11-20}
Twinning
penetration and lamellar on {0001}, {10-12} and {10-12}
Mohs hardness
5.5 - 6.5
Density [g/cm3]
5.2 - 5.3
Cleavage
none
Fracture / Tenacity
brittle, in thin flakes elastic, uneven to conchoidal
Color
metallic-gray, dull to bright red
Streak
bright red to dark red
Transparency
opaque
Optical character
uniaxial (-)
Refractive Index
nω=3.150-3.220; nε=2.870-2.940
Birefringence δ
0.280
Pleochroism δ
moderate to strong