The Wolframite Group

Property Ferberite Wolframite Huebnerite
Formula FeWO4 (Fe, Mn)WO4 MnWO4
WO3 Content (%) 76.3 76.5 76.6
Mn Content (%) 0 – 3.6 3.6 – 14.5 14.5 – 18.1
Fe Content (%) 18.4 – 14.7 14.7 – 3.7 3.7 – 0
Specific Gravity 7.5gr/cc 7.1 – 7.5 gr/cc 7.2 – 7.3 gr/cc
Form well defined crystals irregular groups of radiating crystals radiating thin crystals
Color black dark grey to black red-brown to black
Luster submetallic to metallic submetallic to metallic submetallic to adamantine
Diaphaneity opaque to translucent opaque opaque to translucent
Streak dark brown dark brown red-brown to green-yellow
Crystal Structure monoclinic monoclinic monoclinic
Cleavage 1 direction, perfect 1 direction, perfect 1 direction, perfect
Fracture uneven uneven uneven
Hardness 5 Mohs 5 -5.5 Mohs 5 Mohs
Magnetism feeble slight none