mineral
Magnetite
Iron(II,III) oxide (Fe3O4)
AI-generated identification · may be incorrectHardness: 5.5-6.5; Color: Black to silvery gray; Luster: Metallic to submetallic; Crystal System: Isometric/Octahedral; Cleavage: None/Indistinct; Specific Gravity: 5.1-5.2.
- Hardness
- 5
- Color
- Black to silvery gray
- Luster
- Metallic to submetallic
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Physical properties
Hardness: 5.5-6.5; Color: Black to silvery gray; Luster: Metallic to submetallic; Crystal System: Isometric/Octahedral; Cleavage: None/Indistinct; Specific Gravity: 5.1-5.2.
Formation & geological history
Formed in igneous and metamorphic environments through crystallization from a melt or by hydrothermal replacement. It is often found in contact metamorphic zones and as a detrital mineral in beach sands.
Uses & applications
The primary ore of iron; used in heavy media separation, steel production, and as a natural magnet (lodestone) for early navigation.
Geological facts
Magnetite is the most magnetic of all the naturally-occurring minerals on Earth. It was used by ancient mariners to create the first compass needles.
Field identification & locations
Identified by its strong attraction to magnets and its black streak on a porcelain plate. It is commonly found in banded iron formations and heavy sand deposits.
