Iron Oxide Magnetite type
Fe3O4
Chemical name
Iron Oxide Magnetite type
Mineral name
Magnetite
Chemical formula
Fe3O4
Crystal system
cubic
Crystal Class
cubic-hexoctahedral (4/m -3 2/m)
Space Group
Fd-3m
Unit cell
a [Å]:8.399
b [Å]:8.399
c [Å]:8.399
Formula units
Z=8
Frequent crystal surfaces
{111}, {110}, {100}
Twinning
penetration twinning on (111)
Mohs hardness
5.5 - 6.5
Density [g/cm3]
5.18
Cleavage
on (111)
Fracture / Tenacity
uneven
Color
black
Streak
black
Transparency
opaque, weakly translucent
Optical character
isotropic
Refractive Index
n=2.42
Birefringence δ
none