Magnetite
| Magnetite | |
|---|---|
Magnetite from Bolivia | |
| General | |
| Category |
|
| Formula | 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 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.