Magnetite – Wikipedia

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Magnetite
Category IV : oxides and hydroxides [ first ]
Image illustrative de l’article Magnétite
Magnetite and Pyrite – Italy
General
NOM IUPAC Trip Tetraoxide
Case 1309-38-2 (magnetite)
1317-61-9 (Trip Tetraoxide)
Classe de Strunz
DANA CLASS
Chemical formula Fe 2+ Fe 2 3+ O 4
Identification
Mass form 231.54 One
Color Metal, fat, mat.
Crystalline class and space group hexakisochtahedral;
F d3m
Crystalline system cubic
Bravais network Faces centered f
Macle Macle on {111} by contact
Cleavage partial on {111}
Break irregular, subconchoidal
Habitus Octaedrical crystals
Mohs scale 6
Trait noir
Glow submetallic
Optical properties
Fluorescence ultraviolet none
Transparency opaque
Chemicals
Volumic mass 5.2 g cm −3 To 20 °C g/cm 3
Melting temperature 1 538 °C
Solubility Soluble in hydrochloric acid [ 2 ]
Physical properties
Magnetism strongly magnetic
Radioactivity none
Precautions
Simdut [ 3 ]
Uncontrolled product


SI & CNTP units, unless otherwise indicated.

The magnetite is a mineral species made up of iron oxide (II, III), Formula 3 O 4 (parfois écrit FeO·Fe2O3), avec des traces de magnésium Mg, de zinc Zn, de manganèse Mn, de nickel Ni, de chrome Cr, de titane Ti, de vanadium V et d’aluminium Al. La magnétite est un matériau ferrimagnétique.

Varieties rich in titanium are described as Magnetitites titifers, or more often as Titanomagnetites .

Magnetite crystals can be biomineralized, that is to say biosynthesized by certain living species [ 4 ] , which seem to be able to use them to orient themselves in space.

History of the description and names [ modifier | Modifier and code ]

Etymology [ modifier | Modifier and code ]

Magnetite has been known since at least the Iron Age; The first written mention dates from Pliny the old in 77; It was described by Wilhelm Karl Ritter von Haidinger in 1845; Its name derives from German Magnet , word itself derived from Latin Magnes, magnet Magnetic signifier and ultimately deriving from the name of the province of Magnesia, rich in magnetite.

Topotype [ modifier | Modifier and code ]

Magnési, Theresalie (Greece).

Synonymy [ modifier | Modifier and code ]

  • loving
  • diamagnétite (Shepard 1852) [ 5 ]
  • ferroferrite (le) [ 6 ]
  • magnetic oxidized iron
  • oxidulated iron (Dufrenoy 1845) [ 7 ]
  • Heraclion: magnetite was abundant in Heraclea in Lydia [ 8 ]
  • morpholite
  • magnet stone
  • northern stone

Physical properties [ modifier | Modifier and code ]

Habitus
It forms typically octaédrical crystals, more rarely dodecaécais, exceptionally cubic, which can reach nearly 25 cm [ 9 ] .
Magnetism
At a temperature of 580 °C (point of curia), magnetism disappears to reappear then by cooling. The persistence is around 480 Gauss. This mineral is an electrical driver.

Cristallochimie [ modifier | Modifier and code ]

The Spinelle group

Brings together species of similar structure. There are more than 20 species. The generic formula is xy 2 O 4 Where X represents a divalent metal (magnesium, iron, nickel, manganese and/or zinc) and a trivalent metal (aluminum, iron, chrome and/or manganese, titanium).

Structures de la magnétite (a) et de la maghémite (b)

Crystallography [ modifier | Modifier and code ]

Crystal structure of magnetite

Associated gitology and minerals [ modifier | Modifier and code ]

Gîtology

It is a common ubiquitous mineral, which is found in many types of rocks.

  • Intrusting rocks: in Diorites and Gabbros, as well as in their volcanic equivalents (Andesite and basalt).
  • Metamorphic rocks: classic mineral in skarns, it is introduced by metasomatosis in limestone rocks.
  • Hydrothermal training: it can be present as a mineral accessory. In alpine slots, it exists in very beautiful samples (in Italy and Switzerland).
  • Sedimentary rocks: magnetite can be found as a heavy element detrital in sediments; Magnetite sand deposits are exploited in northern New Zealand.
  • Deposit of volcanic smoking: Vesuvius and de l’Etna; Its facies can be tree or dendritic.
  • Present in some meteorites.
Associated minerals
  • Apatitis, chromite, illemenite, rutile, and silicates in intrusive rocks.
  • Chalcopyrite, hematite pentlandite, pyrite, pyrrhotite, sphalerite, and silicates in hydrothermal and metamorphic rocks
  • Hematite, quartz in sedimentary rocks.

Producer deposits of remarkable specimens [ modifier | Modifier and code ]

It is present in most concentrates of the rock of goldsmiths And can be easily separated using a magnet. It is also found in Austria in green shales where crystals can easily exceed 5 mm edges.

Mally formed crystals of 250 kg were found in Faraday, Ontario in Canada and the Pegmatites de Teete in Mozambique.

Uses
  • It is one of the main iron ores.
  • Color: primary pigment for the land of shadow and the earth of his.
  • Main component of ferrites powder used for the manufacture of magnets.
  • Dating of lavas flows due to its farm properties, magnetite is useful in paleomagnetism because it records the variations in the orientation of the terrestrial magnetic field. Thanks to magnetite, we were able to determine on close flows that each inversion of the terrestrial dipole there is a transition phase of 1,000 years where the magnetic field can be reversed in 3 days.
  • Biology: According to research carried out by two American biologists, Gould and Kirschvink, the cells of the human being contain magnetite crystals, which could lead to understanding the bioelectromagnetic properties of the human body [ ten ] . It was wrongly believed that the pigeon had magnetite, present in three very distinct places and in different quantities, inside his beak, which would have helped him to go in flight [ 11 ] . These statements were however refuted. [ twelfth ] , [ 13 ]
  • Elimination of arsenic in water [ 14 ]

Magnetite is normally present in the form of biomineralized crystals in certain organs in various animal species, where it could play a role in the direction of the orientation [ 15 ] .
In humans we have found it in several areas of the brain, including frontal lobes, parietal lobes, occipital and temporal lobes, but also in the cerebral trunk, the cerebellum and the nodes of the base [ 15 ] , [ 16 ] .
The iron is there in three forms: hemoglobin (circulating in the blood), ferritin (protein) and in small quantities in the form of magnetite. The areas of the brain involved in the motor function generally contain more iron [ 16 ] , [ 17 ] . The hippocampus (information processing area, learning and memory) also contains [ 16 ] .

A hypothesis (biomagnetism), is that, like many animals, the human being has or would have retained a reliclitic meaning [ 18 ] , that some people endowed with a very good sense of orientation would unconsciously use, and this would require the presence of magnetite crystals (reacting to the terrestrial magnetic field) [ 19 ] . The functions of magnetite in the brain are still misunderstood [ 20 ] .

Iron is an absolutely vital trace element, but, at dose abnormally high in the brain, magnetite can have neurotoxic effects, at least because of its charged or magnetic nature and its involvement in oxidative stress or the production of free radicals [ 21 ] ; Indeed it has been shown that beta-amyloid plates and tau protein associated with neurodegenerative diseases occur frequently after oxidative stress and iron biomineralization in the brain [ 16 ] .

The electron microscope makes it easy to distinguish magnetite crystals, naturally produced and stored by body cells (crystals with complex shapes), magnetite from air pollution (smooth and rounded nanoparticles from the exhaust jars and Combustion/incineration process that can go back to the brain along the olfactory nerve, increasing the concentration of magnetite in the brain and introducing an abnormal shape of magnetite) [ 16 ] , [ 21 ] .
Nanoparticles of inhaled magnetitis could also pass into the blood via the lungs and pass through the hematoencephalic barrier. Autopsies (of children and adults) have shown that, in regions where air is very polluted (Mexico City for example), the human brain could contain a rate of magnetite particles up to approximately 100 times higher than the normal, and associated with neuronal degeneration and more or less serious neurodegenerative diseases depending on the case [ 22 ] . This work led by Professor Barbara Maher (University of Lancaster) concludes that a causal link (plausible, but to confirm with Alzheimer’s disease) because in the laboratory studies suggest that Iron oxides magnetite are a component of abnormal protein plates that form Alzheimer’s diseases in the brain [ 23 ] .

Abnormal iron rates (magnetic iron in particular) have been measured in certain areas of the brain of patients victims of Alzheimer’s disease [ 24 ] . Monitoring these rates could be an indicator of loss of neurons and the development of certain neurodegenerative diseases, even before the appearance of symptoms [ 25 ] , [ 24 ] (due to the relationship between magnetite and ferritin) [ 16 ] .
In fabrics, magnetite and ferritin can create small magnetic fields interacting with magnetic resonance imaging (MRI) by creating a contrast on the image [ 24 ] .

Huntington’s disease has never been associated with an increased level of magnetite, but high levels have been found in the animal model (laboratory mouse) [ 16 ] .

  1. The classification of the minerals chosen is that of Strunz, with the exception of the polymorphs of the silica, which are classified among the silicates.
  2. (in) Thomas R. Dulski, A manual for the chemical analysis of metals , vol.  25, ASTM International, , 251 p. (ISBN  0-8031-2066-4 , read online ) , p. 71
  3. Black iron oxide »In the chemical product database Reptox of the CSST (Quebec organization responsible for occupational safety and health), consulted on April 24, 2009
  4. Lownstam HA (1962) Magnetite in denticle capping in recent chitons (Polyplacophora) . Bull. Geol. Soc. Am. 13 , 435-438
  5. Shepard (1852), American Journal of Science : 13: 392.
  6. International conferences of the National Research Center , Number 27 by National Center for Scientific Research (France) p. 80 1950
  7. Treaty of Mineralogy, Volume 2 by bear Pierre Armand Petit Dufrenoy p. 462 1845
  8. Encyclopedia, or reasoned dictionary of science, arts , Volume 17 by Denis Diderot, Jean Le Rond d’Alembert p. 279 1778
  9. The Handbook of Mineralogy Volume IV, 2000 Mineralogical Society of America by Kenneth W. Bladh, Richard A. Bideaux, Elizabeth Anthony-Morton and Barbara G. Nichols
  10. Kirschvink, J.L. and Gould, J.L., “Biogenic magnetite as a basis for magnetic field sensitivity in animals ,” Bio Systems 13 (1981) 181-201.
  11. Marianne Hanzlik, Christoph Heunemann, Elke Holtkamp-Rötzler, Michael Winklhofer, Nikolai Petersen and Gerta Fleissner. Superparamagnetic Magnetite in the Upper Beak Tissue of Homing Pigeons. BioMetals 13 (2000) 325-331
  12. Quentin Mauguit Future , The beak of pigeons is not a compass » , on Future (consulted the )
  13. Zone Science- ICI.RADIO-CANADA.CA , The 6th sense of pigeons remains a mystery » , on Radio-CANADA.CA (consulted the )
  14. Cafer T. Yavuz, J. T. Mayo, Carmen Suchecki, Jennifer Wang, Adam Z. Ellsworth, Helen D’Couto, Elizabeth Quevedo, Arjun Prakash, Laura Gonzalez and Christina Nguyen, et al., “Pollution magnet: nano-magnetite for arsenic removal from drinking water”, Environmental Geochemistry and Health, Volume 32, Number 4, 327-334
  15. a et b Kirschvink J et al. (1992) ” Magnetite biomineralization in the human brain “. Proceedings of the National Academy of Sciences of the USA. 89 (16): 7683–7687. Bibcode:1992PNAS…89.7683K. doi:10.1073/pnas.89.16.7683. Lay summary. “Using an ultrasensitive superconducting magnetometer in a clean-lab environment, we have detected the presence of ferromagnetic material in a variety of tissues from the human brain.”
  16. a b c d e f and g Magnetite Nano-Particles in Information Processing: From the Bacteria to the Human Brain Neocortex (ISBN  9781-61761-839-0 )
  17. Tocca, luigi; Youdim, Moussa B. H .; Riously, peter; Connor, james r .; CRESSION, ROBERT R. (2004). ” Iron, brain ageing and neurodegenerative disorders “. Nature Reviews Neuroscience. 5: 863–873
  18. Eric Hand (June 23, 2016). ” Maverick scientist thinks he has discovered a magnetic sixth sense in humans “. Science. doi:10.1126/science.aaf5803.
  19. Baker, R R (1988). “Human magnetoreception for navigation”. Progress in Clinical and Biological Research. 257: 63–80. PMID 3344279
  20. Kirschvink, Joseph L; Winklhofer, Michael; Walker, Michael M (2010). ” Biophysics of magnetic orientation: strengthening the interface between theory and experimental design “. Journal of the Royal Society, Interface / the Royal Society. 7 Suppl 2: S179–91. doi:10.1098/rsif.2009.0491.focus. PMC 2843999librement accessible. PMID 20071390 .
  21. a et b Barbara A. Maher; IMAD A. M. Ahmed; Vassil Karloukovski; Donald A. Maclaren; Penelope G. Foulds; David Allsop; David M. A. Mann; Ricardo Torres-Jardón; Lilian Calderon-Garcidueas (2016). ” Magnetite pollution nanoparticles in the human brain ” (PDF). PNAS Early Edition. 113 (39): 10797–10801. Bibcode:2016PNAS..11310797M. doi:10.1073/pnas.1605941113. PMC 5047173Freely accessible. PMID 27601646 .
  22. BBC Environment:Pollution particles ‘get into brain’ (Environment: particles from air pollution penetrate the brain
  23. Wilson, Clare (5 September 2016). ” Air pollution is sending tiny magnetic particles into your brain “. New scientist. 231 (3090). Accessed September 06, 2016
  24. A B and C Qin y, zhu w, zhan c et al. (2011) j. Huazhong univ. Sci. Technol. [Med. Sci.] 31: 578.
  25. Tocca, luigi; Youdim, Moussa B. H .; Riously, peter; Connor, james r .; CRESSION, ROBERT R. (2004). ” Iron, brain ageing and neurodegenerative disorders “. Nature Reviews Neuroscience. 5: 863–873.

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