Ferberite
Ferberite
Published: June 2014
Modified: August 2021
Ferberite is an iron-rich mineral commonly seen as a black to dark gray prism-shape specimens with metallic luster. At times it can exhibit weak magnetism and should not be confused with hematite.
General Information
Common Name
Ferberite
Species
Ferberite
Transparency
Semitranslucent - Opaque
Refractive Index
Over The Limit 2.255-2.414
Birefringence
0.159
Optic Character
Biaxial
Optic Sign
Positive
Polariscope Reaction
Doubly Refractive (DR)
Pleochroism
None
Hardness
4-4.5
Streak
Brownish Black To Black
Specific Gravity
7.500-7.600 Typical:7.580
Toughness
Poor
Luster
Adamantine, Metallic
Fracture
Uneven
Cleavage
Perfect, in one direction
Chemical Name
iron tungstate
Chemical Formula
FeWO4
Crystal System
Monoclinic
Chemistry Classification
Oxide
Ferberite Colors
-
Brown -
Black
Countries of Origin
Unknown; China