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| Uvarovite
is named after Count Sergei Semenovich Uvarov (1786-1855),
Russian nobleman, President of Academy of Sciences.
| Discovered
in 1832;
IMA
status:
Valid (pre-IMA; Grandfathered) |
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Chemistry
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Chemical
Formula: |
Ca3Cr2(SiO4)3
|
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Calcium
Chromium Silicate |
Molecular
Weight: |
500.48 gm
|
Composition: |
Calcium |
24.02 % |
Ca |
33.61 % |
CaO |
|
Chromium |
20.78 % |
Cr |
27.17 % |
CrO |
|
Silicon |
16.84 % |
Si |
36.02 % |
SiO2 |
|
Oxygen |
38.36 % |
O |
|
|
|
|
100.00 % |
|
100.00 % |
= TOTAL OXIDE |
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Classification
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Mineral
Classification: |
Silicates
(Germanates)
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Strunz 8th
Ed. ID:
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8/A.08-130
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Nickel-Strunz 10th
Ed. ID:
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9.AD.25
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9 : SILICATES (Germanates)
A : Nesosilicates D : Nesosilicates without additional anions; cations in [6] and/or greater coordination
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Related
to: |
Garnet Group. Grossular-Uvarovite Series.
Ugrandite Series.
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Members
of Group: |
Garnet
Group: Almandine, Andradite, Berzeliite, Bitikleite,
Calderite, Goldmanite, Grossular, Henritermierite, Hibschite,
Katoite, Kerimasite, Kimzeyite, Knorringite, Majorite,
Momoiite, Morimotoite, Pyrope, Schäferite, Schorlomite,
Spessartine, Toturite, Uvarovite, Yafsoanite
|
Varieties: |
None
|
Synonyms: |
Chrome
Garnet, Chromium Garnet, Ouvarovite, Uvarovite Garnet
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Crystal
Data
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Crystallography:
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Isometric
- Hexoctahedral
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Crystal
Habit:
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Commonly
as euhedral crystals, dodecahedra or trapezohedra, or
in combination with other cubic forms, to 4.5 cm. Fine
or coarse granular, compact, or massive.
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Twinning:
|
None
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Physical
Properties
|
|
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Cleavage: |
None
|
Fracture: |
Irregular/Uneven
to Conchoidal
|
Tenacity:
|
Brittle
|
Moh's
Hardness: |
6.5
- 7.0
|
Density:
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3.77
- 3.81 (g/cm3)
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Luminescence:
|
Fluorescent;
red under SW UV and LW UV |
Radioactivity:
|
Not
Radioactive
|
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Optical
Properties
|
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Color: |
Emerald-green
to dark green; in thin section, green; may be sectored.
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Transparency: |
Transparent
to Translucent |
Luster: |
Vitreous
|
Refractive
Index: |
1.865
Isotropic
|
Birefringence: |
0.000
(Isotropic minerals have no birefringence)
|
Dispersion: |
n/a |
Pleochroism: |
None
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Anisotrophism: |
May be weakly anisotropic due to strain or symmetry reduction (triclinic and orthorhombic varieties are known).
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Occurances
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Geological
Setting: |
From
hydrothermal alteration of serpentinite containing chromite;
in metamorphosed limestones and skarns from the reaction
of dolomite and chromite. |
Common
Associations: |
Chromite,
Diopside, Zoisite, Olivine, Dolomite, Tremolite, Quartz,
Plagioclase, Epidote, Calcite, Chromian Clinochlore,
Pyroxenes. |
Common
Impurities: |
Al,
Fe, Mg |
Type
Locality: |
Saranovskii Mine
(Saranovskoe), Saranovskaya (Sarany) Village, Gornozavodskii area,
Permskaya Oblast', Middle Urals, Urals Region, Russia |
Year
Discovered: |
1832
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View
mineral photos: |
Uvarovite
Mineral Photos and Locations |
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More
Information
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|
|
Mindat.org
Webmineral.com
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Uvarovite
is a rare member of the Garnet Group of minerals that includes
Almandine, Andradite, Grossular, Pyrope, Spessartine
and Uvarovite.
Uvarovite has a beautiful emerald-green
color and is the only consistenly green Garnet
variety. The green color is due to the presence of chromium
in its chemistry.
The name has frequently been misused in the past to refer to other green
and/or chromium-bearing garnets. Many so-called 'Uvarovites' are
actually chromian Grossular, chromian Pyrope, green Andradite (the so-called Iranian 'uvarovite') or even the rare Knorringite (magnesium chromium garnet).
Uvarovite crystals are rarely large enough for
faceting and usually available only as "drusy" type
cabochons.
Although
Uvarovite is an uncommon Garnet, there are numerous
localities. From the Saranovskii mine, Biserskoye, in
the Gorozavod district, and other localities around
Yekaterinburg (Sverdlovsk), Ural Mountains, Russia.
Exceptional crystals from Outokumpu, Finland. From Pico
do Posets, near Vénasque, Pyrenees, Spain. In Canada,
at South Ham, Wolfe County, Quebec. In the USA, from
Wood's Chrome mine, Lancaster County, Pennsylvania;
at Riddle, Grant County, Oregon; in the Red Ledge mine,
near Washington, Nevada County, around Newcastle, Placer
County, near New Idria, San Benito County, and elsewhere
in California. On Taiwan, Formosa. From Ergani Maden
and in the Kop Krom [chrome] mine, Kop Mountains, near
Askale, Turkey.
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