# Cubanite > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Cubanite > Markdown URL: https://mediated.wiki/source/Cubanite.md > Source: https://en.wikipedia.org/wiki/Cubanite > Source revision: 1292576252 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) {{Short description|Copper iron sulfide mineral}} {{Infobox mineral | name = Cubanite | boxwidth = | boxbgcolor = | image = Cubanite-47299.jpg | imagesize = 260px | alt = | caption = Striated, cyclically-twinned cubanite crystals from the Chibougamau mines of Quebec (size: 1.5 × 1.3 × 1.0 cm) | category = [Sulfide mineral](/source/Sulfide_mineral) | formula = CuFe2S3 | IMAsymbol=Cbn{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3|pages=291–320|doi=10.1180/mgm.2021.43|bibcode=2021MinM...85..291W|s2cid=235729616|doi-access=free}} | molweight = | strunz = 2.CB.55a | dana = | system = [Orthorhombic](/source/Orthorhombic) | class = Dipyramidal (mmm)
[H-M symbol](/source/H-M_symbol): (2/m 2/m 2/m) | symmetry = ''Pcmn'' | unit cell = a = 6.467(1) Å,
b = 11.117(1) Å,
c = 6.231(2) Å; Z = 4 | color = Bronze to brass-yellow | colour = | habit = Crystals elongated to thick tabular, striated also massive | twinning = Common with twin plane {110} in pairs, also as fourlings and pseudohexagonal sixlings | cleavage = Parting on {110} and {1{{overline|3}}0} | fracture = Conchoidal | tenacity = | mohs = 3.5–4 | luster = Metallic | streak = Black | diaphaneity = Opaque | gravity = 4.0–4.2 | density = | polish = | opticalprop = Distinctly anisotropic on polished surface | refractive = | birefringence = | pleochroism = | 2V = | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = Strongly magnetic | references = [http://www.mindat.org/min-1168.html Mindat.org][http://www.webmineral.com/data/Cubanite.shtml Webmineral][http://rruff.geo.arizona.edu/doclib/hom/cubanite.pdf Handbook of Mineralogy] }} '''Cubanite''' is a [copper](/source/copper) iron [sulfide mineral](/source/sulfide_mineral) that commonly occurs as a minor alteration mineral in [magma](/source/magma)tic [sulfide deposit](/source/sulfide_deposit)s. It has the chemical formula CuFe2S3 and when found, it has a bronze to brass-yellow appearance. On the [Mohs hardness scale](/source/Mohs_scale_of_mineral_hardness), cubanite falls between 3.5 and 4 and has a [orthorhombic crystal system](/source/orthorhombic_crystal_system). Cubanite is chemically similar to [chalcopyrite](/source/chalcopyrite); however, it is the less common copper [iron](/source/iron) sulfide mineral due to crystallization requirements. Cubanite occurs in high temperature [hydrothermal](/source/hydrothermal) mineral deposits with [pyrrhotite](/source/pyrrhotite) and [pentlandite](/source/pentlandite) as intergrowths with chalcopyrite. It results from [exsolution](/source/exsolution) from chalcopyrite at temperatures below 200 to 210 °C. If cubanite is exposed to temperatures above 210 °C, it will transform into isocubanite. After this transformation, if it begins to cool, it will not revert to cubanite.{{Cite journal|last1=Chandra|first1=U.|last2=Parthasarathy|first2=G.|last3=Sharma|first3=P.|date=2010-10-01|title=SYNTHETIC CUBANITE CuFe2S3: PRESSURE-INDUCED TRANSFORMATION TO ISOCUBANITE|url=https://doi.org/10.3749/canmin.48.5.1137|journal=The Canadian Mineralogist|volume=48|issue=5|pages=1137–1147|doi=10.3749/canmin.48.5.1137|bibcode=2010CaMin..48.1137C |issn=0008-4476|url-access=subscription}} Upon its transformation to isocubanite it will lose its highly magnetic property due to its change from an orthorhombic to a [cubic crystal structure](/source/Cubic_crystal_system).{{Cite journal|last1=Sawada|first1=M.|last2=Ozima|first2=M.|last3=Fujiki|first3=Y.|date=1962|title=Magnetic Properties of Cubanite (CuFe2S3)|journal=Journal of Geomagnetism and Geoelectricity|volume=14|issue=2|pages=107–112|doi=10.5636/jgg.14.107|bibcode=1962JGG....14..107S|issn=0022-1392|doi-access=free}} Cubanite has been identified on chondrites and within [dust grain sample](/source/Comet_dust)s and has improved the precision of copper isotope analysis. == Etymology and history == [[File:Cubanite-237462.jpg|left|upright|thumb|Iridescent and highly lustrous brass-yellow cubanite crystal from [Chibougamau](/source/Chibougamau), [Quebec](/source/Quebec) (size: 1.7 x 1.0 x 0.7 cm)]] Cubanite comes from the Spanish word ''Cubano,'' or Cuban in English, and the suffix ''-ite'', when naming a mineral. Cubanite was first described in 1843 for its occurrence in the Mayarí-Baracoa Belt, [HolguÍn Province](/source/Holgu%C3%ADn_Province), [Cuba](/source/Cuba). It may also be referenced as barracanite in some literature. == Association and alteration == As a minor alteration mineral, cubanite can only form when there is hydrothermal alteration of magmatic ores. The ores that are associated with cubanite are unaltered [pyrrhotite](/source/pyrrhotite)-[pentlandite](/source/pentlandite)-[chalcopyrite](/source/chalcopyrite) ores that experience alteration to [millerite](/source/millerite)-[pyrite](/source/pyrite)-chalcopyrite-cubanite ores, like those seen in the Bushveld Complex.{{Cite journal|last1=Holwell|first1=David A.|last2=Adeyemi|first2=Zeinab|last3=Ward|first3=Laura A.|last4=Smith|first4=Daniel J.|last5=Graham|first5=Shaun D.|last6=McDonald|first6=Iain|last7=Smith|first7=Jennifer W.|date=December 2017|title=Low temperature alteration of magmatic Ni-Cu-PGE sulfides as a source for hydrothermal Ni and PGE ores: A quantitative approach using automated mineralogy|journal=Ore Geology Reviews|volume=91|pages=718–740|doi=10.1016/j.oregeorev.2017.08.025|bibcode=2017OGRv...91..718H |issn=0169-1368|doi-access=free|hdl=2381/40374|hdl-access=free}} For cubanite to form from chalcopyrite, a loss of copper relative to sulfur and iron and an increase in iron relative to sulfur must occur. This significant change in mineralogy results crystal structure change from tetragonal chalcopyrite to orthorhombic cubanite. With an increase in temperature above 210 °C, alteration continues and cubanite will transform into isocubanite, an isometric polymorph. There will be no transformation back to cubanite upon the cooling of the isocubanite. == Extraterrestrial cubanite == [[File:Tagish Lake meteorite.jpg|left|thumb|[Tagish Lake](/source/Tagish_Lake) Meteorite, Classified as CI-2 due to presence of chondrules]] Although cubanite forms in hydrothermal mineral deposits, there are occurrences of cubanite that did not form on earth. Cubanite has been found in [carbonaceous chondrite](/source/carbonaceous_chondrite) meteorites, specifically class [CI-chondrites](/source/CI_chondrite), as well as in cometary samples from NASA's [Stardust](/source/Stardust_(spacecraft)) spacecraft.{{Cite journal|last1=Berger|first1=Eve L.|last2=Keller|first2=Lindsay P.|last3=Lauretta|first3=Dante S.|date=2015|title=An experimental study of the formation of cubanite (CuFe2S3) in primitive meteorites|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/maps.12399|journal=Meteoritics & Planetary Science|language=en|volume=50|issue=1|pages=1–14|doi=10.1111/maps.12399|bibcode=2015M&PS...50....1B|s2cid=95725179 |issn=1945-5100|doi-access=free}} Data from the [Itokawa](/source/Itokawa_(asteroid)) asteroid, collected by the [Hayabusa](/source/Hayabusa) spacecraft, indicated that a 2-micrometre grain of cubanite was found on the [S-type asteroid](/source/S-type_asteroid). This is the first time cubanite has been found on another asteroid that was not class C-type. However, further inspection of the sample revealed that the cubanite likely formed exogeneous to the Itokawa body.{{Cite journal|last1=Burgess|first1=Katherine|last2=Stroud|first2=Rhonda|date=August 2020|title=STEM of Three Itokawa Grains: Space Weathering and Presence of Cubanite|journal=Microscopy and Microanalysis|language=en|volume=26|issue=S2|pages=2602–2604|doi=10.1017/S1431927620022151|bibcode=2020MiMic..26S2602B|s2cid=225397714|issn=1431-9276|doi-access=free}} === Synthetic cubanite === Although synthetic and chondritic cubanite have structural variations, synthesis of cubanite still grants insight into the formation of CI-chondrites. Using a lab-based variant of hydrothermal recrystallization, temperatures between 150 and 200 °C, and a pH of 9, scientists were able to determine compositions needed to replicate CI-chondrite mineralogy.  Experiments that began with copper + iron + sulfur, [covellite](/source/covellite) + [troilite](/source/troilite), and copper + sulfur + troilite all formed cubanite. Starting with troilite instead of iron metal reinforces previous studies that sulfides on Cl-chondrites are the resultant of oxidation of troilite by hydrothermal processes. == Copper isotope analysis == Due to its complex growth nature, Cubanite has been the test subject for instrumental preference in copper isotope microanalysis. It was found that ultra violet laser ablation multiple collector [inductively coupled plasma mass spectrometry](/source/inductively_coupled_plasma_mass_spectrometry) (UV-fs-LA-MC-ICP-MS) improves precision in respect to copper isotopes, when compared to the use of near infrared (NIR-fs-LA-MC-ICP-MS) methods.{{Cite journal|last1=IKEHATA|first1=Kei|last2=HIRATA|first2=Takafumi|date=2013|title=Evaluation of UV-fs-LA-MC-ICP-MS for Precise in situ Copper Isotopic Microanalysis of Cubanite|journal=Analytical Sciences|volume=29|issue=12|pages=1213–1217|doi=10.2116/analsci.29.1213|pmid=24334990|issn=0910-6340|doi-access=free|hdl=2241/120627|hdl-access=free}}[[File:ICP-MS.jpg|thumb|[Inductively Coupled Plasma Mass Spectrometry](/source/Inductively_coupled_plasma_mass_spectrometry) (ICP-MS) analytical instrument |none]] ==References== {{Reflist}} {{Commons category|Cubanite}} Category:Sulfide minerals Category:Copper minerals Category:Iron minerals Category:Orthorhombic minerals Category:Minerals in space group 62 {{sulfide-mineral-stub}} --- Adapted from the Wikipedia article [Cubanite](https://en.wikipedia.org/wiki/Cubanite) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Cubanite?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.