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| Hessonite
is named from from the Greek word "hesson"
meaning "inferior", because of its inferior hardness to other
varieties of Garnet. Grossular
is named from the Latin "Ribes Grossularium", the
botanical name for "gooseberry" in reference
to its typical greenish color because the original specimens were this color.
| Discovery
year unknown;
IMA
status:
Not Valid (a variety of Grossular
Garnet) |
|
Chemistry
|
|
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Chemical
Formula: |
Ca3Al2(SiO4)3
+
Fe |
|
Calcium
Aluminum Iron Silicate |
Molecular
Weight: |
450.45 gm |
Composition: |
Calcium |
26.69 % |
Ca |
37.35 % |
CaO |
(Grossular)
|
Aluminum |
11.98 % |
Al |
22.64 % |
Al2O3 |
|
Silicon |
18.71 % |
Si |
40.02 % |
SiO2 |
|
Oxygen |
42.62 % |
O |
|
|
|
|
100.00 % |
|
100.00 % |
= TOTAL OXIDE |
|
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Classification
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Mineral
Classification: |
Silicates
(Germanates)
|
Strunz 8th
Ed. ID:
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8/A.08-70
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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: |
A
variety of Grossular Garnet. Garnet Group. Grossular-Hibschite Series.
Grossular-Katoite Series. Grossular-Uvarovite Series.
Pyrope-Grossular Series.
|
Varieties: |
None
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Synonyms: |
Cinnamite,
Cinnamon Garnet, Cinnamon Stone, Essonite, False Hyacinth,
Hyacinthoid
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Crystal
Data
|
|
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Crystallography:
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Isometric
- Hexoctahedral
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Crystal
Habit:
|
Commonly
in dodecahedra or trapezohedra, up to 15 cm, with striated
faces. Also granular, compact, and massive.
|
Twinning:
|
None
observed
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Physical
Properties
|
|
|
Cleavage: |
None
observed. Parting rarely observed on {110}.
|
Fracture: |
Irregular/Uneven, Sub-Conchoidal
|
Tenacity:
|
Brittle
|
Moh's
Hardness: |
6.5
- 7.0
|
Density:
|
3.594 (g/cm3)
|
Luminescence:
|
Almost always non-fluorescent; may be a weak golden yellow under
LW & SW UV. |
Radioactivity:
|
Not
Radioactive
|
|
|
Optical
Properties
|
|
|
Color: |
Yellow-Green,
pale to dark Green; golden Yellow, Pink, Red, Orange,
Brownish Red, Yellowish Brown; Colorless, White, Gray,
Black; may be sectored: Colorless in thin section.
|
Transparency: |
Transparent
to Opaque
|
Luster: |
Vitreous,
Sub-Vitreous, Resinous
|
Refractive
Index: |
1.731
- 1.754 Isotropic. RI increases with increasing iron contents (usually Fe3+).
|
Birefringence: |
0.000
(Isotropic); may have weak strain birefringence
of 0.0 - 0.005
|
Dispersion: |
Strong
|
Pleochroism: |
None
|
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Occurances
|
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Geological
Setting: |
In
contact and regionally metamorphosed calcareous rocks,
or rocks which have undergone calcium metasomatism;
in some schists and serpentinites. |
Common
Associations: |
Calcite,
Dolomite, Epidote, Clinozoisite, Wollastonite, Scapolite,
Vesuvianite, Diopside, Tremolite, Quartz. |
Common
Impurities: |
Fe
|
Type
Locality: |
Unknown
|
Year
Discovered: |
Unknown
|
View
mineral photos: |
Hessonite
Mineral Photos and Locations |
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More
Information
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|
|
Mindat.org
(Hessonite) Mindat.org
(Grossular) Webmineral.com
(Grossular)
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Hessonite
is the more common variety of Grossular Garnet
which is a member of the Garnet Group of minerals that includes
Almandine, Andradite, Grossular, Pyrope, Spessartine
and Uvarovite.
Other varieties of Grossular Garnet are Hessonite,
Rosolite and Tsavorite. Hessonite is
named from the Greek word
"hesson" meaning "inferior", because of its inferior hardness to other
varieties of Garnet. Hessonite Garnets range in color
from cinnamon-brown to orange and have been called "Cinnamon Garnet" because of its color. The
color is due to the addition of iron to its chemical
formula. Gem quality Hessonite is found in Sri Lanka, Tanzania,
Brazil and California, USA.
Grossular,
also known as Grossularite, is a calcium aluminum variety
of the Garnet Group. The name Grossular is derived from the botanical name for the gooseberry, Ribes Grossularium,
in reference to the green variety of Garnet that was
originally found in the Vilyui River Basin, Eastern-Siberian
Region, Russia. Hessonite,
The name Garnet comes from the Latin word granatus
meaning grain. This is from the comparison of garnet
grains in rock looking like the dark red seeds
of the Pomegranite fruit scattered on the ground. Tsavorite, Rosolite and Viluite are varieties of
Grossular and are not recognized as distinct mineral
species.
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Hessonite
gems for sale:
We
have not photographed our Hessonite gems. Please
check back soon.
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