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| Spessartine
is named after the Spessart Mts, Germany where it was
discovered.
| Discovered
in 1832;
IMA
status: Valid (pre-IMA; Grandfathered) |
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Chemistry
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Chemical
Formula: |
Mn2+3Al2(SiO4)
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Manganese
Aluminum Silicate |
Molecular
Weight: |
495.03 gm
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Composition: |
Manganese |
33.29 % |
Mn |
42.99 % |
MnO |
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Aluminum |
10.90 % |
Al |
20.60 % |
Al2O3 |
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Silicon |
17.02 % |
Si |
36.41 % |
SiO2 |
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Oxygen |
38.78 % |
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/A.08-30
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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.
Almandine-Spessartine Series.
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Members
of Group: |
Garnet
Group: Almandine, Andradite, Grossular, Pyrope, Spessartine, Uvarovite
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Varieties: |
Brandãosite,
Calcium-Eisenspessartin, Emildine, Spandite
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Synonyms: |
Erinite (of van der Lingen),
Mandarin Garnet, Partschinite, Spessartine Garnet, Spessartite
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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 10 cm. Fine
or coarse granular, compact, massive.
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Twinning:
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None
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Physical
Properties
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Cleavage: |
None
(?)
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Fracture: |
Irregular/Uneven
to Conchoidal
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Tenacity:
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Brittle
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Moh's
Hardness: |
7.0
- 7.5
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Density:
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4.190
(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: |
Red,
reddish orange, yellow, yellowish brown, reddish brown,
brown, black; pale pink to pale brown in thin section,
may be sectored.
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Transparency: |
Transparent
to Translucent |
Luster: |
Vitreous
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Refractive
Index: |
1.800 Isotropic
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Birefringence: |
0.000
(Isotropic)
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Dispersion: |
Weak |
Pleochroism: |
None
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Anisotrophism: |
May
show weak anisotropism. |
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Occurances
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Geological
Setting: |
Common
in granite pegmatites, granites, and rhyolites. Formed
in some skarns and metasomatic manganese-rich rocks
adjacent to igneous intrusions or in regionally metasomatized
areas. |
Common
Associations: |
Quartz,
Potassic Feldspar, Tourmaline, Rhodonite, Pyroxmangite,
Tephroite, Alleghanyite, Galaxite, Muscovite, Topaz,
Apatite, Beryl, Albite, Bixbyite, Pseudobrookite. |
Common
Impurities: |
None
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Type
Locality: |
Sommer quarry, Wendelberg, Haibach, Aschaffenburg, Spessart, Franconia, Bavaria, Germany
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Year
Discovered: |
1832
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View
mineral photos: |
Spessartine
Mineral Photos and Locations |
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More
Information
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|
Mindat.org
Webmineral.com
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Spessartine,
also called Spessartite, is a member of the Garnet Group of minerals that includes
Almandine, Andradite, Grossular, Pyrope, Spessartine
and Uvarovite.
Spessartine
is fairly rare as a gem Garnet, and one of the most
beautiful. Large gems are very rare and usually quite
dark. The finest color is an orangy red, as exemplified
by material from Ramona, California, USA and Amelia,
Virginia, USA. A red-brown tint indicates a higher content
of Almandine, accompanied by a higher refractive index;
pale to bright orange colors are closer to pure Spessartine. Bright
orange Spessartine Garnets are often called Mandarin
Garnets.
Spessartine
as a component of Almandine gems tends to add a lively
reddish tinge of color.
Rare
color change Garnets with large amounts of vanadium
(V) and chromium (Cr) have been reported from East Africa.
These are primarily Spessartine, with an unusually large
component of Grossular. There are generally two types
of color change displayed: either greenish yellow-brown
in fluorescent light to purplish red or reddish orange
in incandescent light; or light bluish green in fluorescent
light to purplish red or red in incandescent light.
So-called Alexandrite-like Garnets are also found from
Bekily, Madagascar. These gems display a distinct color
change from violet-red to blue-green.
Spessartine, like other garnets, forms rounded crystals with 12
rhombic or 24 trapezoidal faces or combinations of these and some other
forms.
This crystal habit is classic for the Garnet minerals. Spessartine is
formed in manganese rich metamorphic environments and in some granitic
pegmatites.
Distribution:
While a less-common garnet, nevertheless many localities.
From Aschaffenburg, Spessart Mountains, Bavaria, Germany.
On Seriphos, Cyclades Islands, Greece. In the USA, in
Leiper's quarry, Avondale, Delaware County, Pennsylvania;
the Rutherford mine, Amelia, Amelia County, Virginia;
in the Ramona and Pala districts, San Diego County,
California; from the Thomas Range, Juab County, Utah;
at Ely, White Pine County, Nevada; from near Nathrop,
Chaffee County, Colorado. In Brazil, from Nangue and
Urucum, Minas Gerais, and at Carnaúba, near Picui, Rio
Grande do Norte. From Marienflüss, Namibia. At Tsilaizina
and Anjanabonoina, Madagascar. In the Gilgit district,
and at Dusso, Baltistan, Pakistan. From Broken Hill,
New South Wales, Australia. At Wada-toge Pass, Nagano
Prefecture, Japan.
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Spessartine
gems for sale:
We
have not photographed our Spessartine gems yet. Please
check back soon.
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