The Wolframite Group Properties

 Property

 ferberite

 wolframite

 huebnerite

 Picture

 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