Magnetite

Magnetite
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
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
Major varieties
Lodestone	Magnetic with definite north and south poles

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]

^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
^ 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.
^ ^a ^b ^c Hurlbut, 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.

[1] Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.

[Handbook-2] 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.

[Mindat-3] "Magnetite". mindat.org and the Hudson Institute of Mineralogy. Retrieved 15 November 2018.

[Webmin-4] Barthelmy, Dave. "Magnetite Mineral Data". Mineralogy Database. webmineral.com. Retrieved 15 November 2018.

[5] Hurlbut, Cornelius S.; Klein, Cornelis (1985). Manual of Mineralogy (20th ed.). Wiley. ISBN 978-0-471-80580-9.

[Ferrimag2005-6] 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.

[Dana-7] Hurlbut, 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-8] 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.

[9] 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.

[Tremolet-10] Du Trémolet de Lacheisserie, Étienne; Damien Gignoux; Michel Schlenker (2005). Magnetism: Fundamentals. Springer. pp. 3–6. ISBN 0-387-22967-1.

[11] Nesse, William D. (2000). Introduction to mineralogy. New York: Oxford University Press. p. 361. ISBN 9780195106916.

[12] 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.

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