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| Uvite is
named for the Type Locality area, Uva Province, Sri Lanka.
| Discovered
in 1929;
IMA
status:
Valid (IMA redefined, approved 2010) |
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Chemistry
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Chemical
Formula: |
(Ca,Na)(Mg,Fe2+)3Al5Mg(BO3)3Si6O18(OH,F)4 |
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Calcium
Sodium Magnesium Iron Aluminum Boro-Silicate Hydroxide
Fluoride |
Molecular
Weight: |
970.23 gm
|
Composition: |
Sodium |
0.59 % |
Na |
0.80 % |
Na2O |
|
Calcium |
3.10 % |
Ca |
4.33 % |
CaO |
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Magnesium |
5.64 % |
Mg |
9.35 % |
MgO |
|
Aluminum |
13.90 % |
Al |
26.27 % |
Al2O3 |
|
Iron |
4.32 % |
Fe |
5.55 % |
FeO |
|
Silicon |
17.37 % |
Si |
37.16 % |
SiO2 |
|
Boron |
3.34 % |
B |
10.76 % |
B2O3 |
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Hydrogen |
0.31 % |
H |
2.79 % |
H2O |
|
Oxygen |
49.47 % |
O |
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|
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Fluorine |
1.96 % |
F |
1.96 % |
F |
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|
- % |
F |
-0.82 % |
-O=F2 |
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|
100.00 % |
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98.14 % |
= TOTAL OXIDE |
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Classification
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Mineral
Classification: |
Silicates
(Germanates)
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Strunz 8th
Ed. ID:
|
8/E.19-90
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Nickel-Strunz 10th
Ed. ID:
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9.CK.05
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9 : SILICATES (Germanates)
C : Cyclosilicates K : [Si6O18]12- 6-membered single rings, with insular complex anions
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Related
to: |
Tourmaline
Group. Dravite - Uvite Series. The Mg-analogue of
Feruvite.
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Members
of Group: |
Tourmaline
Group: Buergerite, Chromdravite, Dravite, Elbaite, Feruvite,
Fluor-Dravite, Fluor-Schorl, Foitite, IMA2009-088, Liddicoatite, Luinaite-(OH),
Magnesiofoitite, Olenite, Oxy-Dravite, Oxy-Rossmanite,
Oxy-Schorl, Povondraite, Rossmanite, Schorl, Uvite, Vanadiumdravite.
|
Varieties: |
None
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Synonyms: |
IMA2000-030a
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Crystal
Data
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Crystallography:
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Trigonal
- Ditrigonal Pyramidal
|
Crystal
Habit:
|
Crystals
prismatic to equant, may be tabular, pyramidal, in radiating
groups, to 15 cm. Cross sections are typically triangular
with curved, convex sides.
|
Twinning:
|
None
|
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Physical
Properties
|
|
|
Cleavage: |
Indistinct
on {1011}
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Fracture: |
Irregular/Uneven,
Conchoidal
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Tenacity:
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Brittle
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Moh's
Hardness: |
7.5
|
Density:
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2.97
- 3.14 (g/cm3)
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Luminescence:
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May fluoresce
a weak mustard-yellow under SW
UV. |
Radioactivity:
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Not
Radioactive |
Other: |
Piezoelectric
and Pyroelectric
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Optical
Properties
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Color: |
Light
to dark
green, yellowish brown, red, brown, blackish brown, black,
colorless;
may be zoned parallel to prism faces. |
Transparency: |
Semi-Transparent,
Translucent, Opaque |
Luster: |
Vitreous,
Resinous, Greasy |
Refractive
Index: |
1.637
- 1.668 Uniaxial ( - ) |
Birefringence: |
0.0180
- 0.0290 |
Dispersion: |
n/a |
Pleochroism: |
Weak;
O
= pale yellow; E
= colorless
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Occurances
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Geological
Setting: |
Typically
in calcium-rich rocks subjected to contact metamorphism
and metasomatic processes which added boron. |
Common
Associations: |
Calcite,
Dolomite, Tremolite, Apatite, Scapolite |
Common
Impurities: |
Mn,
Ti, Na, Cr, V, Zn, H2O
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Type
Locality: |
Uva Province, Sri Lanka
|
Year
Discovered: |
1929
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View
mineral photos: |
Uvite
Mineral Photos and Locations |
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More
Information
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|
Mindat.org
Webmineral.com
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Uvite
is a rare member of the Tourmaline Group
of minerals
that includes Achroite,
Dravite, Liddicoatite,
Povondraite,
Rubellite, Schorl
and Uvite.
Uvite
is a magnesium/iron
rich
member of the Tourmaline Group. Uvite was once considered
to be a very rare variety of the Tourmaline Group but
has recently become more readily available on the gem
and mineral markets. Other more common and more well
know Tourmalines are Elbaite (various colors and colorless,
lithium rich), Schorl (opaque black, iron rich), Dravite
and Liddicoatite. Most colored Tourmaline used as gemstones are Elbaite
Tourmaline. Uvite is
named for the Type Locality area, Uva Province, Sri Lanka
and is available in colors of light
to dark
green, yellowish brown, red, brown, blackish brown, black,
colorless and may be zoned parallel to prism faces.
Distribution:
In
Uva Province, Sri Lanka. From the Sagaing district,
Myanmar (Burma). In the USA, from Franklin and Hamburg,
Sussex County, New Jersey; in New York, at Gouverneur,
Pierrepont, Dekalb and elsewhere in St. Lawrence County,
and at Horicon, Warren County; and from East Hampton, Middlesex
County, Connecticut. From Brumado, Bahia, Brazil. At Hnústa,
Slovakia.
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Uvite
gems for sale:
We
have not photographed the Uvite gems yet. Please
check back soon.
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