{{Short description|Nickel antimony sulfide mineral}} {{Other uses|Nickel glance (disambiguation)}} {{Infobox mineral | name = Ullmannite | category = Sulfide mineral | boxwidth = | boxbgcolor = | image = Ullmannite - Mt Narba - Sardinia.JPG | imagesize = 260px | caption = | formula = NiSbS | IMAsymbol = Ull<ref>{{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}}</ref> | strunz = 2.EB.25 | system = Cubic | class = Tetartoidal (23) <br/>H-M symbol: (23) | symmetry = ''P''2<sub>1</sub>3 | unit cell = a = 5.91(2) Å; Z = 4 | molweight = | color = Steel-gray to tin white | habit = | twinning = Penetration twins about [110] | cleavage = Perfect on {001} | fracture = Uneven | tenacity = Brittle | mohs = 5–5.5 | luster = metallic | streak = | diaphaneity = Opaque | gravity = 6.65–6.85 | density = | polish = | opticalprop = | refractive = | birefringence = | pleochroism = | 2V = | dispersion = | extinction = | length fast/slow = | fluorescence= | absorption = | melt = | fusibility = | diagnostic = | solubility = | other = | alteration = | references = <ref name=HBM>[http://rruff.geo.arizona.edu/doclib/hom/ullmannite.pdf Handbook of Mineralogy]</ref><ref name=Webmin>[http://webmineral.com/data/Ullmannite.shtml Webmineral data]</ref><ref name=Mindat>[http://www.mindat.org/show.php?id=4086&ld=1&pho= Mindat with location data]</ref> }}
'''Ullmannite''' or ''Nickel glance'' (trivial name) is a nickel antimony sulfide mineral with formula: NiSbS. Considerable substitution occurs with cobalt and iron in the nickel site along with bismuth and arsenic in the antimony site. A solid solution series exists with the high cobalt willyamite.
==Physical properties== Ullmannite is steel-gray to tin white in color with a metallic luster, has a Mohs hardness of 5 to 5.5 and a specific gravity of 6.65. Initially thought to be of two species, tetrahedral and cubic, it was later confirmed that both samples conformed to the 23 point group of the isometric crystal class and typically exhibits cubic, octahedral, or pyritohedral forms although euhedral crystals are rare.<ref name="Miers-1891">{{cite journal |last=Miers |first=A.H. |year=1891 |title=The Tetardohedrism of Ullmannite. |journal=Mineralogical Magazine |volume=9 |issue=43 |pages=211–213 |doi=10.1180/minmag.1891.009.43.03|bibcode=1891MinM....9..211M }}</ref>
Variance in its chemical composition has been shown to be responsible for loss of symmetry and variations in striation patterns.<ref name="Takeuchi-1957">{{cite journal |last=Takeuchi |first=Y. |year=1957 |title=The Absolute Structure of Ullmannite, NiSbS. |journal=Mineralogical Journal |volume=2 |issue=2 |pages=90–102 |url=http://www.journalarchive.jst.go.jp/english/jnlabstract_en.php?cdjournal=minerj1953&cdvol=2&noissue=2&startpage=90 |doi=10.2465/minerj1953.2.90 |bibcode=1957MinJ....2...90T |doi-access=free }}{{Dead link|date=May 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>
Ullmannite crystals are usually less than 2 mm, however larger have been identified in especially antimony rich environments.<ref name="Zhu-2010">{{cite journal |last=Zhu |first=Y. |author2=An, F. |year=2010 |title=Native Antimony in the Baogutu gold deposit( West Junggar, NW China): Its occurrence and origin |journal=Ore Geology Reviews |volume=37 |issue=3–4 |pages=214–223 |doi=10.1016/j.oregeorev.2010.03.005|bibcode=2010OGRv...37..214A }}</ref> Ullmannite commonly displays interpenetration twins as well as enantiomorphic twinning along [110].<ref name=HBM/>
==Occurrence== thumb|left|Ullmannite crystals from the Masaloni Mine, San Vito, Cagliari Province, Sardinia, Italy (size: 5.4 × 3.3 × 2.1 cm) It is a member of the cobaltite group and forms a series with willyamite ({{chem2|(Co,Ni)SbS}}). It occurs with nickeline, gersdorffite, pentlandite, chalcopyrite, pyrrhotite, galena, tetrahedrite and dyscrasite in hydrothermal deposits.<ref name=HBM/>
Principal localities are in Germany, it is also found in Austria, Australia, France, England, and Wales.
It was first described in 1843 for an occurrence in the Storch und Schöneberg Mine, North Rhine-Westphalia, Germany.<ref name=Mindat/>
Specimens of ullmannite were found at Sarrabus, Sardinia, Italy in 1887. The crystals of the specimens from Sarrabus were described as hemihedral with parallel faces, whereas specimens from Lölling in present-day Austria were hemihedral with inclined faces.<ref name="Klein-1888">{{cite journal |last=Klein |first=C. |author2=P. Jannasch |year=1888 |title=Ullmannite from Lölling and from Sarrabus. (''Jahrb. F. Min.'', 1887, ii, Mem., 169–173) |journal=Journal of the Chemical Society, Abstracts |volume=54 |page=31 |url=https://books.google.com/books?id=ldY4AAAAMAAJ&dq=Sarrabus&pg=PA31 |access-date=December 23, 2010}}</ref>
==Origin of name== Ullmannite was named for German chemist and mineralogist, Johann Christoph Ullmann (1771–1821), one of the fathers of systematic mineralogy. Ullmann established a mineral collection (now the basis for the internationally renowned Museum of Mineralogy in Marburg<ref>{{cite web | url=http://www.uni-marburg.de/fb19/minmus | title=Geographie }}</ref>) and authored ''Ein Systematisch-Tabellarische Übersicht der Mineralogisch einfachen Fossilien'', one of the first attempts to provide a structured organization to the observed minerals of the day.
==See also== *List of minerals *List of minerals named after people
==References== {{Reflist}} * Palache, C., H. Berman, and C. Frondel (1944) ''Dana’s system of mineralogy'', (7th edition), v. I, 301–302.
{{Commons category|Ullmannite}}
{{Antimonides}}
Category:Nickel minerals Category:Antimonide minerals Category:Sulfide minerals Category:Cubic minerals Category:Glances Category:Minerals in space group 198 Category:Minerals described in 1843