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| Ullmannite
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Discovered
in 1843; IMA
status:
Valid (pre-IMA; Grandfathered)
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Chemistry
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Chemical
Formula: |
NiSbS
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Nickel
Antimony Sulfide |
Molecular
Weight: |
212.51 gm
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Composition: |
Nickel |
27.62 % |
Ni |
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Antimony |
57.29 % |
Sb |
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Sulfur |
15.09 % |
S |
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100.00 % |
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Classification
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Mineral
Classification: |
Sulfides
and Sulfosalts
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Strunz 8th
Ed. ID:
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2/D.18-40
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Nickel-Strunz 10th
Ed. ID:
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2.EB.25
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2 : SULFIDES and SULFOSALTS (sulfides, selenides,
tellurides; arsenides, antimonides, bismuthides; sulfarsenites,
sulfantimonites, sulfbismuthites, etc.) E : Metal Sulfides, M: S <= 1:2
B : M:S = 1:2, with Fe, Co, Ni, PGE, etc.
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Related
to: |
Cobaltite Group. Ullmannite-Willyamite Series.
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Members
of Group: |
Cobaltite Group:
Changchengite, Cobaltite, Gersdorffite, Hollingworthite,
Irarsite, Jolliffeite, Kalungaite, Maslovite, Mayingite,
Michenerite, Milotaite, Padmaite, Platarsite, Testibiopalladite,
Tolovkite, Ullmannite, Willyamite
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Varieties: |
None
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Synonyms: |
Antimonikel (of Beudant),
Antimon-nickel (of Beudant), Hartmannite, Nickelspiesglaserz,
Nickel-stibine
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Crystal
Data
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Crystallography:
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Isometric - Tetartoidal
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Crystal
Habit:
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As
cubes and, less commonly, octahedra, pyritohedra, tetrahedra,
to 3 cm. Cube faces striated by [110], twin boundaries
of enantiomorphs.
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Twinning:
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Forms
penetration twins about [110] with {001} the approximate
composition plane; re-entrants develop on cube edges.
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Physical
Properties
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Cleavage: |
Perfect
on {001}
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Fracture: |
Irregular/Uneven
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Tenacity:
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Brittle
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Moh's
Hardness: |
5.0
- 5.5; Vickers: VHN100=592-627 kg/mm2
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Density:
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6.65
- 6.85 (g/cm3)
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Luminescence:
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None
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Radioactivity:
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Not
Radioactive
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Optical
Properties
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Color: |
Steel-gray
to silver-white; white in reflected light
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Transparency: |
Opaque
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Luster: |
Metallic |
Refractive
Index: |
R:
(400) 52.0, (420) 51.0, (440) 50.0, (460) 49.0, (480)
48.2, (500) 47.4, (520) 46.7, (540) 46.1, (560) 45.7,
(580) 45.5, (600) 45.5, (620) 45.6, (640) 46.0, (660)
46.4, (680) 47.0, (700) 47.6
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Birefringence: |
0.000
(opaque)
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Dispersion: |
None |
Pleochroism: |
None |
Anisotropism: |
Individuals
may be weakly anisotropic revealing a fine lamellar
structure.
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Occurances
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Geological
Setting: |
With
nickel minerals in hydrothermal veins. |
Common
Associations: |
Nickeline,
Gersdorffite, Pentlandite, Chalcopyrite, Pyrrhotite,
Galena, Tetrahedrite, Dyscrasite |
Common
Impurities: |
Fe,
Co, As, Bi |
Type
Locality: |
Storch und Schöneberg Mine, Gosenbach, Siegerland, North Rhine-Westphalia, Germany
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Year
Discovered: |
1843
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View
mineral photos: |
Ullmannite
Mineral Photos and Locations |
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Unusual
Gem Categories
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Metallic
Gems |
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More
Information
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Mindat.org
Webmineral.com
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Ullmannite
is a rare nickel
antimony sulfide mineral and a member of the Cobaltite Group
of minerals that also includes Cobaltite and Gersdorffite
among others. Ullmannite has a steel-gray to silver-white
color and metallic luster with a Mohs hardness of 5.0
- 5.5. It is very similar to the nickel arsenic sulfide called
Gersdorffite. Gersdorffite's formula is NiAsS compared
to Ullmannite's formula of NiSbS. Gersdorffite's formula shows
the substitution of arsenic (As) for the antimony (Sb)
in Ullmannite's formula, although Ullmannite usually
has some arsenic in its chemistry. Ullmannite is rarer
than Gersdorffite but the two minerals are almost indistinguishable
from each other by ordinary evaluation means.
Ullmannite
was named after Johann Christoph Ullmann (1771-1821), German mineralogist and chemist.
Ullmann is considered to be one of the fathers of systematic mineralogy. Ullmann established a
mineral collection (now the basis for the internationally renowned
Museum of Mineralogy in Marburg) 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.
Ullmannite
distribution: in Germany, in North Rhine-Westphalia,
from Freusburg at the Friedrich mine, near Wissen; the
Petersbach mine, near Eichelhardt; Gosenbach; Salchendorf;
and at Ramsbeck; in the Harz Mountains, from Neudorf;
and elsewhere From Lölling, Carinthia, Austria.
In France, at Ar, near Eaux-Bonnes, Pyrénées-Atlantiques.
From Monte Narba and Masaloni, Sarrabus, Sardinia, Italy.
In the Settlingstones mine, Fourstones, Northumberland,
and at New Brancepeth colliery, Durham, England. From
the Talnakh area, Noril’sk region, western Siberia,
Russia. In the Esperanza mine, Salta Province, Argentina.
In Canada, at the Kerr Addison mine, Timiskaming district,
Ontario; and from the Nicholson mine, near Goldfields,
Saskatchewan. At Broken Hill, New South Wales, Australia.
In the Champion Reef mine, Kolar Gold Fields, Karnataka,
India. Dozens of additional minor localities are known.
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