Maghemite
A variety of Minerals
What is Maghemite?
Maghemite (Fe2O3, γ-Fe2O3) is a member of the family of iron oxides. It has 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 ( Fe 8 III ) A [ Fe 40 3 III ◻ 8 3 ] B O 32 {\displaystyle \left({\ce {Fe^{III}8}}\right)_{A}\left[{\ce {Fe_{40/3}^{III}\square _{8/3}}}\right]_{B}{\ce {O32}}} where ◻ {\displaystyle \square } represents a vacancy, A indicates tetrahedral and B octahedral positioning.
Uses & Applications
Maghemite exhibits ferrimagnetic ordering with a high Néel temperature (~950 K), which together with its low cost and chemical stability led to its wide application as a magnetic pigment in electronic recording media since the 1940s. Maghemite nanoparticles are also used in biomedicine, because they are biocompatible and non-toxic to humans, while their magnetism allows remote manipulation with external fields.
Market Value Factors
Pricing varies for every rock and mineral, so use these universal factors to gauge Maghemite before comparing listings or appraisals.
Size & Weight
Larger, intact specimens usually command higher prices.
Rarity & Demand
Scarce material or popular varieties sell at a premium.
Condition & Finish
Chips, repairs, and heavy wear lower value; clean prep helps.
Treatment & Provenance
Untreated specimens with documented locality are prized.
Maghemite Localities Map
See where Maghemite is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.
Key Characteristics
Formation of Maghemite
Maghemite forms by weathering or low-temperature oxidation of spinels containing iron(II) such as magnetite or titanomagnetite. Maghemite can also form through dehydration and transformation of certain iron oxyhydroxide minerals, such as lepidocrocite and ferrihydrite. It occurs as widespread brown or yellow pigment in terrestrial sediments and soils. It is associated with magnetite, ilmenite, anatase, pyrite, marcasite, lepidocrocite and goethite. It is known to also form in areas that have been subjected to bushfires (particularly in the Leonora area of Western Australia) magnetising iron minerals. Maghemite was named in 1927 for an occurrence at the Iron Mountain mine, northwest of Redding, Shasta County, California. The name alludes to somewhat intermediate character between MAGnetite and HEMatite. It can appear blue with a grey shade, white, or brown. It has isometric crystals. Maghemite is formed by the topotactic oxidation of magnetite.
Quick Facts
Physical Properties
- Color
- Brown, brick-red
- Hardness (Mohs)
- 6
- Streak
- Brown
Chemical Properties
- Chemical Formula
- (Fe3+0.67◻0.33)Fe3+2O4
- Elements
- Fe, O
Also Known As
Identify Maghemite Instantly
- Snap a photo, get instant results
- 6,700+ rocks, minerals & crystals
- Discover collecting spots near you
Maghemite FAQs
How do I identify Maghemite?
Maghemite can be identified by its hardness of 6 on the Mohs scale, Brown color. Look for these key characteristics when examining specimens.
What color is Maghemite?
Maghemite typically appears in Brown, brick-red. Color can vary depending on impurities and formation conditions.
How hard is Maghemite?
Maghemite has a hardness of 6 on the Mohs scale. This gives it moderate hardness.
What is the formation of maghemite of Maghemite?
Maghemite forms by weathering or low-temperature oxidation of spinels containing iron(II) such as magnetite or titanomagnetite. Maghemite can also form through dehydration and transformation of certain iron oxyhydroxide minerals, such as lepidocrocite and ferrihydrite. It occurs as widespread brown or yellow pigment in terrestrial sediments and soils. It is associated with magnetite, ilmenite, anatase, pyrite, marcasite, lepidocrocite and goethite. It is known to also form in areas that have been subjected to bushfires (particularly in the Leonora area of Western Australia) magnetising iron minerals. Maghemite was named in 1927 for an occurrence at the Iron Mountain mine, northwest of Redding, Shasta County, California. The name alludes to somewhat intermediate character between MAGnetite and HEMatite. It can appear blue with a grey shade, white, or brown. It has isometric crystals. Maghemite is formed by the topotactic oxidation of magnetite.
%252FAbenakiite-(ce)-01.jpg&size=small)
