This article is about the mineral magnetite as found in natural deposits. For other uses, see Iron(II,III) oxide.
Not to be confused with magnesite.
Magnetite
Magnetite from Bolivia
General
Category
Oxide minerals
Spinel group
Spinel structural group
Formula (repeating unit)
iron(II,III) oxide, Fe2+Fe3+2O4
IMA symbol
Mag[1]
Strunz classification
4.BB.05
Crystal system
Isometric
Crystal class
Hexoctahedral (m3m) H-M symbol: (4/m 3 2/m)
Space group
Fd3m (no. 227)
Unit cell
a = 8.397 Å; Z = 8
Identification
Color
Black, gray with brownish tint in reflected sun
Crystal habit
Octahedral, fine granular to massive
Twinning
On {Ill} as both twin and composition plane, the spinel law, as contact twins
Cleavage
Indistinct, parting on {Ill}, very good
Fracture
Uneven
Tenacity
Brittle
Mohs scale hardness
5.5–6.5
Luster
Metallic
Streak
Black
Diaphaneity
Opaque
Specific gravity
5.17–5.18
Solubility
Dissolves slowly in hydrochloric acid
References
[2][3][4][5]
Major varieties
Lodestone
Magnetic with definite north and south poles
Magnetite is one of the very few minerals that is ferrimagnetic; it is attracted by a magnet as shown hereUnit cell of magnetite. The gray spheres are oxygen, green are divalent iron, blue are trivalent iron. Also shown are an iron atom in an octahedral space (light blue) and another in a tetrahedral space (gray).
Magnetite is a mineral and one of the main iron ores, with the chemical formula Fe2+Fe3+2O4. It is one of the oxides of iron, and is ferrimagnetic;[6] it is attracted to a magnet and can be magnetized to become a permanent magnet itself.[7][8] With the exception of extremely rare native iron deposits, it is the most magnetic of all the naturally occurring minerals on Earth.[7][9] Naturally magnetized pieces of magnetite, called lodestone, will attract small pieces of iron, which is how ancient peoples first discovered the property of magnetism.[10]
Magnetite is black or brownish-black with a metallic luster, has a Mohs hardness of 5–6 and leaves a black streak.[7] Small grains of magnetite are very common in igneous and metamorphic rocks.[11]
The chemical IUPAC name is iron(II,III) oxide and the common chemical name is ferrous-ferric oxide.[12]
^Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W. "Magnetite" (PDF). Handbook of Mineralogy. Chantilly, VA: Mineralogical Society of America. p. 333. Retrieved 15 November 2018.
^"Magnetite". mindat.org and the Hudson Institute of Mineralogy. Retrieved 15 November 2018.
^Barthelmy, Dave. "Magnetite Mineral Data". Mineralogy Database. webmineral.com. Retrieved 15 November 2018.
^Hurlbut, Cornelius S.; Klein, Cornelis (1985). Manual of Mineralogy (20th ed.). Wiley. ISBN 978-0-471-80580-9.
^Jacobsen, S.D.; Reichmann, H.J.; Kantor, A.; Spetzler, H.A. (2005). "A gigahertz ultrasonic interferometer for the diamond anvil cell and high-pressure elasticity of some iron-oxide minerals". In Chen, J.; Duffy, T.S.; Dobrzhinetskaya, L.F.; Wang, Y.; Shen, G. (eds.). Advances in High-Pressure Technology for Geophysical Applications. Elsevier Science. pp. 25–48. doi:10.1016/B978-044451979-5.50004-1. ISBN 978-0-444-51979-5.
^ abcHurlbut, Cornelius Searle; W. Edwin Sharp; Edward Salisbury Dana (1998). Dana's minerals and how to study them. John Wiley and Sons. pp. 96. ISBN 978-0-471-15677-2.
^Wasilewski, Peter; Günther Kletetschka (1999). "Lodestone: Nature's only permanent magnet - What it is and how it gets charged". Geophysical Research Letters. 26 (15): 2275–78. Bibcode:1999GeoRL..26.2275W. doi:10.1029/1999GL900496. S2CID 128699936.
^Harrison, R. J.; Dunin-Borkowski, RE; Putnis, A (2002). "Direct imaging of nanoscale magnetic interactions in minerals". Proceedings of the National Academy of Sciences. 99 (26): 16556–16561. Bibcode:2002PNAS...9916556H. doi:10.1073/pnas.262514499. PMC 139182. PMID 12482930.
^Du Trémolet de Lacheisserie, Étienne; Damien Gignoux; Michel Schlenker (2005). Magnetism: Fundamentals. Springer. pp. 3–6. ISBN 0-387-22967-1.
^Nesse, William D. (2000). Introduction to mineralogy. New York: Oxford University Press. p. 361. ISBN 9780195106916.
^Morel, Mauricio; Martínez, Francisco; Mosquera, Edgar (October 2013). "Synthesis and characterization of magnetite nanoparticles from mineral magnetite". Journal of Magnetism and Magnetic Materials. 343: 76–81. Bibcode:2013JMMM..343...76M. doi:10.1016/j.jmmm.2013.04.075.
Magnetite is a mineral and one of the main iron ores, with the chemical formula Fe2+Fe3+2O4. It is one of the oxides of iron, and is ferrimagnetic; it...
or deep purple to rusty red. The iron is usually found in the form of magnetite (Fe 3O 4, 72.4% Fe), hematite (Fe 2O 3, 69.9% Fe), goethite (FeO(OH),...
Lodestones are naturally magnetized pieces of the mineral magnetite. They are naturally occurring magnets, which can attract iron. The property of magnetism...
a lipid bilayer membrane. Each magnetosome can often contain 15 to 20 magnetite crystals that form a chain which acts like a compass needle to orient...
is typically dark grey or blackish in colour. It is composed mainly of magnetite, Fe3O4, and also contains small amounts of titanium, silica, manganese...
twinning, which forms the lattice pattern. Magnetite (Fe3O4) forms black, equilateral triangles. The magnetite that has no alteration is black with a metallic...
Centrex Metals Limited is an Australian resources exploration and mining company. Founded in 2001, Centrex Metals was listed on the Australian Securities...
high-purity magnetite (Fe3O4). The pulverized iron is oxidized to give magnetite or wüstite (FeO, ferrous oxide) particles of a specific size. The magnetite (or...
commonly present as magnetite, iron silicates, and iron-bearing carbonates, and locally martite (hematite) formed by oxidation of magnetite. Horizons containing...
as magnetite (Fe3O4) and is also ferrimagnetic. It is sometimes spelled as "maghaemite". Maghemite can be considered as an Fe(II)-deficient magnetite with...
(antigorite, lizardite, chrysotile), brucite, talc, Ni-Fe alloys, and magnetite. The mineral alteration is particularly important at the sea floor at...
of hematite. Another example is hematite Fe3+ 2O 3 on magnetite Fe2+ Fe3+ 2O 4. The magnetite structure is based on close-packed oxygen anions stacked...
Fe2+(Fe3+,Ti)2O4. It is also known as titaniferous magnetite, mogensenite, Ti-magnetite, or titanian magnetite. It is part of the spinel group of minerals....
Gabbro Crest, Sheriff Cliffs, Fierle Peak, Dyrdal Peak, Mount Stephens, Magnetite Bluff, Mathis Spur, Burmester Dome and Huie Cliffs. Features in the snowfield...
(FeO), the second cycle is a conversion step between wuestite (FeO) and magnetite (Fe3O4). In application, the SIT is used in the reformer sponge iron cycle...
wüstite), iron(III) oxide (Fe2O3, hematite), and iron(II,III) oxide (Fe3O4, magnetite). Mill scale is formed on the outer surfaces of plates, sheets or profiles...
people noticed that lodestones, naturally magnetized pieces of the mineral magnetite, could attract iron. The word magnet comes from the Greek term μαγνῆτις...
perhaps as much as 50% of the mass, may be in titanium enriched magnetite (Fe3O4). Magnetite is usually black in colour with a black streak, and does not...
2010. It was closed in 2014. IMX shifted its focus to the Mount Woods Magnetite Project. IMX owns and operates the highly prospective Nachingwea Regional...
gradients that are smaller than one hundred tesla per meter. Monodisperse magnetite ( Fe 3 O 4 {\displaystyle {\ce {Fe3O4}}} ) and nanocrystals ( NCs {\displaystyle...
Pieces of magnetite with natural permanent magnetization (lodestones) provided the earliest compasses for navigation. Particles of magnetite were extensively...
Verwey transition is a low-temperature phase transition in the mineral magnetite associated with changes in its magnetic, electrical, and thermal properties...
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