Magnetite

Natural magnets (lodestones) were known to ancient Greeks, who called this mineral "magnet", because it was found in the lands of the Magnetes (Magnesia) in Thessaly.

Magnetite is a heavy material, black or brownish-black with a metallic luster. It is the most magnetic of all natural commonly occurring minerals on the Earth.

The originally bright black colour can gradually change to dark brown.

Magnetite is often used in jewelry due to its supposed magnetic healing properties.

Magnetite Gemstones by Colour

This table shows the variety of hues this gemstone can be found in. Click on a photo for more information.
 
General Information
Chemical Formula
Fe
 
3
O
 
4
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
More from other references
Photos of natural/un-cut material from mindat.org
Physical Properties of Magnetite
Mohs Hardness5.5 to 6.5
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
Specific Gravity5.2
Walter Schumann, Gemstones of the world (2001)
More from other references
TenacityBrittle
Gemdat.org, Management Team (2012)
Cleavage QualityGood
Gemdat.org, Management Team (2012)
FractureUneven,Irregular
Gemdat.org, Management Team (2012)
Optical Properties of Magnetite
Refractive Index2.42
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
Optical CharacterIsotropic
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
Colour
Colour (General)Black
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
More from other references
TransparencyOpaque
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
LustreMetallic
Walter Schumann, Gemstones of the world (2001)
More from other references
Crystallography of Magnetite
Crystal SystemIsometric
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
Further Information
Mineral information:Magnetite information at mindat.org
Significant Gem Localities
Kyrgyzstan
 
  • Naryn Oblast
Thailand
 
  • Trat Province
    • Bo Rai District
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