Not to be confused with Magnesite, Magnetite, or Magnemite.
Maghemite
General
Category
Oxide minerals
Formula (repeating unit)
γ-Fe2O3
IMA symbol
Mgh[1]
Strunz classification
4.BB.15
Crystal system
Cubic with a tetragonal supercell
Crystal class
Gyroidal (432) (same H-M symbol)
Space group
P4132, P4332
Unit cell
a = 8.33 Å; Z = 8 or a = 8.35 Å c = 24.99 Å; Z = 8 for tetragonal supercell
Identification
Color
Brown, bluish black; brown to yellow in transmitted light; white to bluish gray in reflected light.
Crystal habit
Rarely as minute octahedral crystals, or acicular overgrowths; commonly as coatings on or replacements of magnetite; massive.
Cleavage
None
Fracture
Subconchoidal
Mohs scale hardness
5
Luster
Dull
Streak
Brown
Diaphaneity
Opaque, transparent in thin fragments
Specific gravity
4.860 (calculated)
Optical properties
Isotropic
Other characteristics
Strongly magnetic
References
[2][3][4][5]
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 (Fe3O4) and is also ferrimagnetic. It is sometimes spelled as "maghaemite".
Maghemite can be considered as an Fe(II)-deficient magnetite with formula
[6] where
represents a vacancy, A indicates tetrahedral and B octahedral positioning.
^Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C., eds. (1997). "Maghemite" (PDF). Handbook of Mineralogy. Vol. III (Halides, Hydroxides, Oxides). Chantilly, VA, US: Mineralogical Society of America. ISBN 0962209732.
^Maghemite. Mindat
^Maghemite. Webmineral
^Cornell, R. M. and Schwertmann, Udo (2003) The Iron Oxides: Structure, Properties, Reactions, Occurrences and Uses. Wiley-VCH. p. 32. ISBN 3527302743.
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...
nanoparticles or iron oxide nanoparticles (iron oxides in crystal structure of maghemite or magnetite) are the most explored magnetic nanoparticles up to date...
goethite and ferrihydrite convert to maghemite on exposure to heat. Temperatures sufficient to elevate maghemite on a landscape scale indicate the influence...
Hematite is not only harder than pure iron, but also much more brittle. Maghemite is a polymorph of hematite (γ-Fe 2O 3) with the same chemical formula...
two main forms are composed of magnetite (Fe3O4) and its oxidized form maghemite (γ-Fe2O3). They have attracted extensive interest due to their superparamagnetic...
⇒ γ-Li 2ZnSiO 4 An alternate example is the oxidation of magnetite to maghemite. IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book")...
lodestones has found them to be made of magnetite (Fe3O4) with inclusions of maghemite (cubic Fe2O3), often with impurity metal ions of titanium, aluminium,...
composition as maghemite; to distinguish between them, their chemical formulae are generally given as γFe2O3 for hematite and αFe2O3 for maghemite. The other...
also thought to form in soils, where they probably oxidize rapidly to maghemite. The chemical composition of magnetite is Fe2+(Fe3+)2(O2-)4. This indicates...
magnetic materials by weight. The magnetic chemicals could be magnetite and maghemite, which could come from the weathering of basalt rock. Subsequent experiments...
; et al. (2010). "Rapid magnetic heating treatment by highly charged maghemite nanoparticles on Wistar rats exocranial glioma tumors at microliter volume"...
iron oxides and iron oxyhydroxides (magnetite, hematite, lepidocrocite, maghemite, goethite); Sedimentation fouling by silt and other relatively coarse...
the airborne dust did not contain pure magnetite or just one type of maghemite. The dust probably was an aggregate possibly cemented with ferric oxide...
and he suggested in 2019 that the tetrahedral coordination arises from maghemite and magnetite impurities observed by electron microscopy. Because of the...
together with quartz, mullite and the iron oxides hematite, magnetite and/or maghemite. Other phases often identified are cristobalite, anhydrite, free lime...
The pits contained red ochre consisting of the iron oxides hematite and maghemite and were covered with a lid. ”This indicates, that even though the palm...
other notable magnetic studies on NPs are those on nearly defect-free maghemite NPs, ferrihydrite NPs undoped and doped with Ni, Mo, and Ir, CdSe quantum...
conducted exploring when magnetite went under low-temperature oxidation to a maghemite. The results showed that this was not a truly effective method die to...
magnetite or maghemite whilst leaving other minerals largely unaffected. This process changes paramagnetic haematite into ferromagnetic maghemite/magnetite...
Global Information
![{\displaystyle \left({\ce {Fe^{III}8}}\right)_{A}\left[{\ce {Fe_{40/3}^{III}\square _{8/3}}}\right]_{B}{\ce {O32}}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/797ed8ea95a1dfbedcb8667ed5cd71f0dac35ace)
