Tungstates and Phosphates: Wolframite
(including Arsenates and Vanadates)

Composition: (Fe,Mn)WO₄; wolframite with 20-80 atomic percent iron is the common form; the names huebnerite and ferberite are used when tungsten and iron are predominant respectively

Crystal system: Monoclinic; crystals commonly prismatic, also massive or lamellar forms

8.7.1
wolframite crystals in quartz
Wolfram Camp Qld Australia

Properties:

• Resinous to submetallic lustre depending on iron content
• Brown to black color
• Brown streak
• Knife scratches easily (Mohs Hardness 4-4.5)
• Very high density
• One perfect cleavage
• Cleaves rather than fractures
• May be weakly ferromagnetic depending on iron content
• Does not react with hydrochloric acid (HCl)

Occurrence:

Wolframite occurs with quartz , cassiterite, scheelite and sulfides in hydrothermal vein deposits associated with granitic rocks.

8.7.2
wolframite crystals in quartz
Wolfram Camp Qld Australia

Wolframite is an important source of tungsten that is used mainly in the manufacture of tungsten carbide and in the electrical industry.