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Vesuvianite (also known as Idocrase)
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Discovered in 1795; IMA status: Valid (pre-IMA; Grandfathered)
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Chemistry
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Chemical
Formula: |
(Ca,Na)19(Al,Mg,Fe)13(SiO4)10(Si2O7)4(OH,F,O)10
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Calcium
Aluminum Magnesium Iron Silicate Hydroxide
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Molecular
Weight: |
1,422.09 gm
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Composition: |
Calcium |
28.18 % |
Ca |
39.43 % |
CaO |
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Magnesium |
3.42 % |
Mg |
5.67 % |
MgO |
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Aluminum |
7.59 % |
Al |
14.34 % |
Al2O3 |
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Silicon |
17.77 % |
Si |
38.03 % |
SiO2 |
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Hydrogen |
0.28 % |
H |
2.53 % |
H2O |
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Oxygen |
42.75 % |
O |
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100.00 % |
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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/C.26-10
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Nickel-Strunz 10th
Ed. ID:
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9.BG.35
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9 : SILICATES (Germanates)
B : Sorosilicates G : Sorosilicates with mixed SiO4 and Si2O7 groups; cations in octahedral [6] and greater coordination
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Related
to: |
Vesuvianite
Group. Hydroxyl analogue of Fluorvesuvianite.
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Members
of Group: |
Vesuvianite
Group: Fluorvesuvianite,
Manganvesuvianite, Vesuvianite, Wiluite
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Varieties: |
Alumovesuvianite, Beryllian Vesuvianite, Californite, Cerian Vesuvianite, Chrome-Vesuvianite,
Cyprine, Egeran, Fluorvesuvianite, Frugardite, High-Hydrated Si-Deficient Vesuvianite,
Manganidocrase, Magnesiovesuvianite, Manganoan Vesuvianite, Manganvesuvianite, Xanthite
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Synonyms: |
Gahnite, Genevite, Gökumite, Heteromerite, Hyacinth, Hyacinthine, Idocrase, Jefreinoffite, Jevreinovite, Loboite, Pyramidal Garnet, Vesuviana, Volcanic Chrysotile
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Crystal
Data
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Crystallography:
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Tetragonal
- Dipyramidal
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Crystal
Habit:
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Crystals commonly
as short pyramidal to long prismatic crystals, to 15
cm, morphologically complex, with up to 30 forms reported
on one crystal; columnar, granular, massive. Californite
is found in massive form, not as crystals.
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Twinning:
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Twinned
domains observed at a very fine scale.
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Physical
Properties
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Cleavage: |
Indistinct
on {110}, {100} and {001]
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Fracture: |
Irregular/Uneven, Sub-conchoidal
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Tenacity:
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Brittle
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Moh's
Hardness: |
6.0
- 7.0 |
Density:
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3.32 - 3.47 (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: |
Green,
Brown, Colorless to White, Blue (Cyprine),
Violet, Bluish green, Pink, Red, Black, commonly zoned;
in transmitted light, Colorless to light Yellow, Green,
Brown |
Transparency: |
Transparent,
Translucent |
Luster: |
Vitreous,
Resinous |
Refractive
Index: |
1.698 - 1.742 Uniaxial
( -/+ ) and Biaxial |
Birefringence: |
0.0040
- 0.0060 |
Dispersion: |
Strong;
0.019 - 0.025 |
Pleochroism: |
Weak;
O
= colorless to yellowish, E = yellowish, greenish,
brownish
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Occurances
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Geological
Setting: |
In
skarns formed during contact or regional metamorphism
of limestones; in garnetized gabbros, mafic and ultramafic
rocks, and serpentinites; uncommon in alkalic igneous
rocks.
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Common
Associations: |
Grossular,
Diopside, Wollastonite, Epidote, Scapolite, Spinel,
Calcite
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Common
Impurities: |
Fe,
Be, B, F, Cu, Li, Na, K, Mn, Ti, Cr, Zn, H2O
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Type
Locality: |
Monte Somma, Somma-Vesuvius Complex, Naples Province, Campania, Italy
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Year
Discovered: |
1795
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View
mineral photos: |
Vesuvianite
Mineral Photos and Locations |
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More
Information
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Mindat.org
Webmineral.com
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Vesuvianite, also known as Idocrase, is a silicate mineral that is a member of the Vesuvianite mineral group that includes Cyprine, Vesuvianite and Wiluite. Vesuvianite is found in colors
ranging from green to brown and also a blue variety
called Cyprine.
yprine is colored blue by the addition
of copper to its chemistry and is also refered to as
Cupreous Idocrase
or Cupreous Vesuvianite. The complexities of Vesuvianite's chemistry leads to the wide range of colors and properties. The green variety is similar in color to Peridot gems. The name Idocrase is a popular synonym of Vesuvianite. Vesuvianite is an IMA approved mineral name, Idocrase is not.
Vesuvianite was named in 1795 by German geologist Abraham Gottlob Werner (1749-1817) from its discovery locality on Mt. Vesuvius, Campania, Italy. However, Vesuvianite was not this mineral's original name though. It has had many names over its history. It was originally named "hyacinthus dictus octodecahedricus" in 1723 by Swiss naturalist Moritz Anton Kappeler (1685-1769). It was renamed "hyacinte du Vesuve" in 1772 by French mineralogist Jean-Baptiste Louis Romé de L'Isle (1736-1790). It was renamed "hyacinthine" in 1792 by French mineralogist Jean-Claude Delamétherie (1743-1817). It was named "vesuvian" twice, once in 1794 by Irish geologist Richard Kirwan (1733-1812) and again in 1795 by German geologist Abraham Gottlob Werner (1749-1817). Vesuvianite was renamed Idocrase in 1796 by French mineralogist René Just Haüy (1743-1822). The name Idocrase is from the Greek words idos and krasis, meaning mixed appearance due to its varied crystal shapes.
A variety of Vesuvianite from California, USA and has been nick-named Californite or California Jade. This bright green opaque to translucent material comes from near Happy Jack mine, Siskiyou County and near Pulga, Butte County, California.
There
are many sources of Vesuvianite such as Asbestos, Quebec, Canada; California,
Colorado and the New England region of USA; Mt.
Vesuvius, Italy; Ural Mountains, Russia, Switzerland, Tanzania and Kenya.
However, there are only a few sources of gem quality crystals. A small amount
of gemmy material has come from Asbestos, Quebec, Canada.
Recent finds in Tanzania and Kenya have brought some
very nicely colored gems to the market.
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Vesuvianite
gems for sale:
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Gem:
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Vesuvianite |
Stock
#:
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VESUV-001 |
Weight:
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1.8070
ct |
Size: |
8.89
x 6.92 x 3.96 mm |
Shape: |
Rectangle |
Color: |
Green |
Clarity: |
Eye
Clean |
Origin: |
Magadi,
Kenya |
Treatment: |
None
(natural) |
Price: |
SOLD
(but we have others) |
Pictures
are of the actual gem offered for
sale. Gem images are magnified to
show detail. |
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A
beautiful Vesuvianite with great color
from southern Kenya.
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Gem:
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Vesuvianite |
Stock
#:
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VESUV-002 |
Weight:
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0.4540
ct |
Size: |
6.87
x 2.98 x 2.06 mm |
Shape: |
Rectangle |
Color: |
Golden
Green |
Clarity: |
Eye
Clean |
Origin: |
Mt.
Vesuvius, Italy |
Treatment: |
None
(natural) |
Price: |
SOLD
(but we have others) |
Pictures
are of the actual gem offered for
sale. Gem images are magnified to
show detail. |
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A
very rare gem from the type locality
for Vesuvianite; Mt. Vesuvius, Somma-Vesuvius
Complex, Naples Province, Campania, Italy.
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