Mackinawite

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Mackinawite
Mackinawite-95018.jpg
General
Category Sulfide mineral
Formula
(repeating unit)		(Fe,Ni)
1+xS (where x=0 to 0.11)
IMA symbol Mkw [1]
Strunz classification 2.CC.25
Crystal system Tetragonal
Crystal class Ditetragonal dipyramidal (4/mmm)
H-M symbol: (4/m 2/m 2/m)
Space group P4/nmm
Unit cell a = 3.67 Å, c = 5.03 Å; Z = 2
Identification
Formula mass 85.42 g/mol
ColorBronze to white grey
Crystal habit As well-formed thin tabular crystals; massive, fine-feathery
Cleavage Perfect on {001}
Mohs scale hardness2.5
Luster Metallic
Streak Black
Diaphaneity Opaque
Specific gravity 4.17
References [2] [3] [4] [5]

Mackinawite is an iron nickel sulfide mineral with the chemical formula (Fe,Ni)
1+xS (where x = 0 to 0.11). The mineral crystallizes in the tetragonal crystal system and has been described as a distorted, close packed, cubic array of S atoms with some of the gaps filled with Fe. [6] Mackinawite occurs as opaque bronze to grey-white tabular crystals and anhedral masses. It has a Mohs hardness of 2.5 and a specific gravity of 4.17. It was first described in 1962 for an occurrence in the Mackinaw mine, Snohomish County, Washington for which it was named. [5]

Contents

Occurrence

Mackinawite occurs in serpentinized peridotites as a hydrothermal alteration product, in meteorites, and in association with chalcopyrite, cubanite, pentlandite, pyrrhotite, greigite, maucherite, and troilite. [3] Mackinawite also occurs in reducing environments such as freshwater and marine sediments as a result of the metabolism of iron and sulfate-reducing bacteria.

In anoxic environments, mackinawite is formed by the reaction of HS− with either Fe2+ ions or with Fe metal. [7] Mackinawite is a metastable mineral that occurs predominantly as a poorly crystalline precipitate. [8] After the initiation of precipitation, mackinawite can take up to 2 years to form at 25 °C. [9] It has been reported that mackinawite can be stable for up to 16 weeks at temperatures up to 100 °C at pH values from 3–12. [10] Laboratories have also produced synthetic mackinawite to study its formation using several different methods such as reacting sulfide with metallic iron or a solution of ferrous iron, growing sulfide reducing bacteria using Fe2+, and electrochemically. [11] [7] [12] [10] [13]

Transformations in the environment

Depending on the redox conditions mackinawite can form more stable phases such as greigite [14] and ultimately pyrite, [15] an important mineral in anoxic aqueous settings that is preserved in sedimentary deposits, especially black shale. [10] [16] [17] [18] [19] [20] While it has been determined that mackinawite is a necessary precursor to pyrite, the pathway of iron sulfide mineral formation from aqueous species to solid mineral is still nebulous. Many iron sulfide minerals may exist in the transition between poorly ordered mackinawite and crystalline pyrite such as greigite, smithite, and pyrrhotite; [21] [22] however, studies have also indicated that pyrite formation from mackinawite can occur where oxidation has commenced and the sulfur present is in intermediate oxidation states (−1 to +6) and intermediate sulfur species such as elemental sulfur or polysulfides and surface oxidized monosulfide species, such as oxidized mackinawite or greigite are present. [10]

See also

Related Research Articles

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<span class="mw-page-title-main">Pentlandite</span> Iron–nickel sulfide

Pentlandite is an iron–nickel sulfide with the chemical formula (Fe,Ni)9S8. Pentlandite has a narrow variation range in nickel to iron ratios (Ni:Fe), but it is usually described as 1:1. In some cases, this ratio is skewed by the presence of pyrrhotite inclusions. It also contains minor cobalt, usually at low levels as a fraction of weight.

<span class="mw-page-title-main">Arsenopyrite</span> Iron-arsenic sulfide mineral

Arsenopyrite is an iron arsenic sulfide (FeAsS). It is a hard metallic, opaque, steel grey to silver white mineral with a relatively high specific gravity of 6.1. When dissolved in nitric acid, it releases elemental sulfur. When arsenopyrite is heated, it produces sulfur and arsenic vapor. With 46% arsenic content, arsenopyrite, along with orpiment, is a principal ore of arsenic. When deposits of arsenopyrite become exposed to the atmosphere, the mineral slowly converts into iron arsenates. Arsenopyrite is generally an acid-consuming sulfide mineral, unlike iron pyrite which can lead to acid mine drainage.

<span class="mw-page-title-main">Chalcopyrite</span> Copper iron sulfide mineral

Chalcopyrite ( KAL-kə-PY-ryte, -⁠koh-) is a copper iron sulfide mineral and the most abundant copper ore mineral. It has the chemical formula CuFeS2 and crystallizes in the tetragonal system. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green-tinged black.

<span class="mw-page-title-main">Sphalerite</span> Zinc-iron sulfide mineral

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<span class="mw-page-title-main">Covellite</span> Sulfide mineral

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<span class="mw-page-title-main">Pyrrhotite</span> Magnetic iron sulfide mineral

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<span class="mw-page-title-main">Marcasite</span> Iron disulfide (FeS2) with orthorhombic crystal structure

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<span class="mw-page-title-main">Fukuchilite</span>

Fukuchilite, Cu
3FeS
8, is a copper iron sulfide named after the Japanese mineralogist Nobuyo Fukuchi (1877–1934), that occurs in ore bodies of gypsum-anhydrite at the intersection points of small masses of barite, covellite, gypsum and pyrite, and is mostly found in the Hanawa mine in the Akita prefecture of Honshū, Japan where it was first discovered in 1969. It occurs in masses within the third geologic unit of the Kuroko type deposits within the mine.

<span class="mw-page-title-main">Troilite</span> Rare iron sulfide mineral: FeS

Troilite is a rare iron sulfide mineral with the simple formula of FeS. It is the iron-rich endmember of the pyrrhotite group. Pyrrhotite has the formula Fe(1-x)S which is iron deficient. As troilite lacks the iron deficiency which gives pyrrhotite its characteristic magnetism, troilite is non-magnetic.

<span class="mw-page-title-main">Greigite</span> Iron sulfide mineral of spinel structure

Greigite is an iron sulfide mineral with the chemical formula Fe2+Fe3+2S4. It is the sulfur equivalent of the iron oxide magnetite (Fe3O4). It was first described in 1964 for an occurrence in San Bernardino County, California, and named after the mineralogist and physical chemist Joseph W. Greig (1895–1977).

Violarite (Fe2+Ni23+S4) is a supergene sulfide mineral associated with the weathering and oxidation of primary pentlandite nickel sulfide ore minerals.

<span class="mw-page-title-main">Cubanite</span> Copper iron sulfide mineral

Cubanite is a copper iron sulfide mineral that commonly occurs as a minor alteration mineral in magmatic sulfide deposits. It has the chemical formula CuFe2S3 and when found, it has a bronze to brass-yellow appearance. On the Mohs hardness scale, cubanite falls between 3.5 and 4 and has a orthorhombic crystal system. Cubanite is chemically similar to chalcopyrite; however, it is the less common copper iron sulfide mineral due to crystallization requirements.

Iron(II,III) sulfide is a blue-black (sometimes pinkish) chemical compound of iron and sulfur with formula Fe3S4 or FeS·Fe2S3, which is much similar to iron(II,III) oxide. It occurs naturally as the sulfide mineral greigite and is magnetic. It is a bio-mineral produced by and found in magnetotactic bacteria. It is a mixed valence compound, featuring both Fe2+ and Fe3+ centers, in 1:2 ratio.

<span class="mw-page-title-main">Millerite</span> Nickel sulfide mineral

Millerite is a nickel sulfide mineral, NiS. It is brassy in colour and has an acicular habit, often forming radiating masses and furry aggregates. It can be distinguished from pentlandite by crystal habit, its duller colour, and general lack of association with pyrite or pyrrhotite.

Mineral processing and extraction of metals are very energy-intensive processes, which are not exempted of producing large volumes of solid residues and wastewater, which also require energy to be further treated and disposed. Moreover, as the demand for metals increases, the metallurgical industry must rely on sources of materials with lower metal contents both from a primary and/or secondary raw materials. Consequently, mining activities and waste recycling must evolve towards the development of more selective, efficient and environmentally friendly mineral and metal processing routes.

References

  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.
  2. ↑ Mineralienatlas
  3. 1 2 Handbook of Mineralogy
  4. ↑ Webmineral data
  5. 1 2 Mindat
  6. ↑ Taylor, L.A.; Finger, L.W. (1970). "Structural refinement and composition of mackinawite". Carnegie Institute of Washington Geophysical Laboratory Annual Report. 69: 318–322.
  7. 1 2 Lennie, A.R.; Redfern, A.T.R.; Champness, P.E.; Stoddart, C.P.; Schofield, P.F.; Vaughn, D.J. (1997). "Transformation of mackinawite to greigite: An in situ X-ray powder diffraction and transmission electron microscope study" (PDF). American Mineralogist. 82 (3–4): 203–309. Bibcode:1997AmMin..82..302L. doi:10.2138/am-1997-3-408. S2CID   18814494.
  8. ↑ Vaughn, D.J.; Craig, J.R. (1978). Mineral chemistry of metal sulfides. Cambridge University Press. ISBN   978-0521214896.
  9. ↑ Rickard, D.T. (1995). "Kinetics of FeS precipitation: Part 1. Competing reaction mechanisms". Geochimica et Cosmochimica Acta. 59 (21): 4367–4379. Bibcode:1995GeCoA..59.4367R. doi:10.1016/0016-7037(95)00251-T.
  10. 1 2 3 4 Benning, L.G.; Wilkin, R.T.; Barnes, H.L. (2000). "Reaction pathways in the Fe–S system below 100°C". Chemical Geology. 167 (1–2): 25–51. Bibcode:2000ChGeo.167...25B. doi:10.1016/S0009-2541(99)00198-9.
  11. ↑ Yamaguchi, S.; Moori, T. (1972). "Electrochemical Synthesis of Ferromagnetic Fe3 S 4". Journal of the Electrochemical Society. 119 (8): 1062. doi:10.1149/1.2404398.
  12. ↑ Mullet, M.; Boursiquot, S.; Abdelmoula, M.; Génin, J.-M.; Ehrhardt, J.-J. (2002). "Surface chemistry and structural properties of mackinawite prepared by reaction of sulfide ions with metallic iron". Geochimica et Cosmochimica Acta. 66 (5): 829–836. Bibcode:2002GeCoA..66..829M. doi:10.1016/S0016-7037(01)00805-5.
  13. ↑ Michel, F.M.; Antao, S.M.; Chupas, P.J.; Lee, P.L.; Parise, J.B.; Schoonen, M.A.A. (2005). "Short- to medium-range atomic order and crystallite size of the initial FeS precipitate from pair distribution function analysis". Chemistry of Materials. 17 (25): 6246–6255. doi:10.1021/cm050886b.
  14. ↑ Csákberényi-Malasics, D., Rodriguez-Blanco, J.D., Kovács Kis, V., Rečnik, A., Benning, L.G., and Pósfai, M. (2012) Structural properties and transformations of precipitated FeS. Chemical Geology, 294–295, 249–258. doi: 10.1016/j.chemgeo.2011.12.009.
  15. ↑ Schoonen, M.A.A. (2004). "Mechanisms of sedimentary pyrite formation". In Amend, J.P.; Edwards, K.J.; Lyons, T.W. (eds.). Sulfur biogeochemistry : past and present. Geological Society of America special papers 379. pp. 117–134. ISBN   9780896299054.
  16. ↑ Cahill, C.L.; Benning, L.G.; Barnes, H.L.; Parise, J.B. (2000). "In situ time-resolved X-ray diffraction of iron sulfides during hydrothermal pyrite growth". Chemical Geology. 167 (1–2): 53–63. Bibcode:2000ChGeo.167...53C. doi:10.1016/S0009-2541(99)00199-0.
  17. ↑ Rickard, D.T.; Morse, J.W. (2005). "Acid volatile sulfide (AVS)". Marine Chemistry. 97 (3–4): 141–197. doi:10.1016/j.marchem.2005.08.004.
  18. ↑ Pósfai, M.; Dunin-Borkowski, R.E. (2006). "Sulfides in Biosystems" (PDF). Reviews in Mineralogy and Geochemistry. 61 (1): 679–714. Bibcode:2006RvMG...61..679P. doi:10.2138/rmg.2006.61.13.
  19. ↑ Hunger, S.; Benning, L.G. (2007). "Greigite: a true intermediate on the polysulfide pathway to pyrite". Geochemical Transactions. 8: 1–20. doi: 10.1186/1467-4866-8-1 . PMC   1847509 . PMID   17376247.
  20. ↑ Rickard, D.T.; Luther, G.W. (2007). "Chemistry of iron sulfides". Chemical Reviews. 107 (2): 514–562. doi:10.1021/cr0503658. PMID   17261073.
  21. ↑ Rickard, D.T. (1969). "The chemistry of iron sulphide formation at low temperatures". Stockholm Contributions in Geology. Vol. 20. pp. 67–95.
  22. ↑ Wuensch, B.J.; Prewitt, C.T.; Rajamani, V.; Scott, S.D.; Craig, J.R.; Barton, P.B. (1974). Sulfide Mineralogy: Short Course Notes. Mineralogical Society of America. ISBN   978-0939950010.
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