maghemite
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Maghemite (Fe2O3, γ-Fe2O3) is a member of the family of iron oxides. It has the same formula as hematite, but the same spinel ferrite structure as magnetite () and is also ferrimagnetic. It is sometimes spelled as "maghaemite".
Key facts
- Mineral.name
- Maghemite
- Mineral.category
- Oxide minerals
- Mineral.image
- Maghemite - Mineralogisches Museum Bonn.jpg
- Mineral.imagesize
- 260px
- Mineral.formula
- γ-Fe2O3
- Mineral.IMAsymbol
- Mgh
- Mineral.strunz
- 4.BB.15
- Mineral.system
- Cubic with a tetragonal supercell
- Mineral.class
- Gyroidal (432) (same H-M symbol)
- Mineral.symmetry
- P4132, P4332
- Mineral.unit cell
- a = 8.33 Å; Z = 8 or a = 8.35 Å c = 24.99 Å; Z = 8 for tetragonal supercell
- Mineral.color
- Brown, bluish black; brown to yellow in transmitted light; white to bluish gray in reflected light.
- Mineral.habit
- Rarely as minute octahedral crystals, or acicular overgrowths; commonly as coatings on or replacements of magnetite; massive.
- Mineral.cleavage
- None
- Mineral.fracture
- Subconchoidal
- Mineral.mohs
- 5
- Mineral.luster
- Dull
- Mineral.streak
- Brown
via Wikipedia infobox
~3 min read
Encyclopedic overview
6 sectionsContents
- Occurrence
- Cation distribution
- Electronic structure
- Applications
- As pollutant
- References
Maghemite (Fe2O3, γ-Fe2O3) is a member of the family of iron oxides. It has the same formula as hematite, but the same spinel ferrite structure as magnetite () and is also ferrimagnetic. It is sometimes spelled as "maghaemite".
Maghemite can be considered as an Fe(II)-deficient magnetite with formula \left(\ce{Fe^{III}8}\right)_A\left[\ce{Fe^{III}_{40/3}\square_{8/3}}\right]_B\ce{O32} where \square represents a vacancy, A indicates tetrahedral and B octahedral positioning.
Excerpted from Wikipedia’s “maghemite” article, available under the CC BY-SA 4.0 licence.