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| Chemistry:
LiAlSi2O6
+ Cr | Discovered
about 1879;
IMA
status: Hiddenite: Not Valid; Spodumene: Valid Hiddenite is named after William
Earl Hidden (1853 - 1918), owner of a mine in North
Carolina near where it was discovered. The name Spodumene
is from the Greek word spodumenos, meaning burnt
to ash which refers to the ashy gray color of early
mineral specimens. |
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Classification
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Mineral
Classification: |
Silicates |
Strunz 8th
Ed. ID:
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8/F.01-120 |
Nickel-Strunz 10th
Ed. ID:
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9.DA.30 |
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9 : SILICATES (Germanates) D : Inosilicates A :
Inosilicates with 2-periodic single chains, Si2O6;
pyroxene family
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Related
to: |
Pyroxene Group,
Clinopyroxene Subgroup. Members include Aegirine,
Augite, Clinoenstatite, Clinoferrosilite, Diopside,
Esseneite, Hedenbergite, Jadeite, Jervisite, Johannsenite,
Kosmochlor, Kanoite, Namansilite, Natalyite, Petedunnite,
Pigeonite and Spodumene.
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Crystal
Data
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Crystallography:
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Monoclinic
- Prismatic
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Crystal
Habit:
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Spodumene:
Crystals are prismatic, typically flattened and striated,
to 12.5 m and 54 t. Commonly massive.
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Twinning:
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Common
on [100]
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Physical
Properties
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Cleavage: |
[110]
Good, [100] Good, [010] Partings
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Fracture: |
Uneven
to Subconchoidal
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Tenacity:
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Brittle
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Hardness
(Mohs): |
6.5 - 7.0 |
Density:
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3.03
- 3.23 (g/cm3) |
Luminescence:
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May
show Yellow, Orange or Pink fluorescence under LW and
SW UV. |
Radioactivity:
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Not
Radioactive |
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Optical
Properties
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Color: |
Light Green
to Emerald-Green
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Transparency: |
Transparent,
Translucent |
Luster: |
Vitreous,
Dull |
Refractive
Index: |
1.653
- 1.682 Biaxial ( + ) |
Birefringence: |
0.014 - 0.018 |
Dispersion: |
Weak;
r < v; 0.012 |
Pleochroism: |
Distinct; X
= Colorless; Y = Emerald Green; Z = Bluish
Green or Greenish Yellow
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Occurances
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Geological
Setting: |
A
common constituent of lithium-rich granite pegmatites;
in aplites and gneisses. |
Common
Associations: |
Quartz,
Albite, Petalite, Eucryptite, Lepidolite, Beryl |
Type
Locality: |
Hiddenite, Alexander Co., North Carolina, USA |
Year
Discovered: |
About
1879
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View
mineral photos: |
Hiddenite
Mineral Photos and Locations |
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More
Information
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Mindat.org
(Hiddenite) Mindat.org
(Spodumene) Webmineral.com
(Spodumene) |
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Hiddenite
is a very rare member of the Spodumene Family of minerals that also
includes
Kunzite. Hiddenite was discovered in Alexander
County, North Carolina, USA and named after William
Earl Hidden, owner of a mine in North
Carolina near where it was discovered. The nearby town
of White Plains was renamed Hiddenite after the beautiful
green mineral. The name Hiddenite was originally used
to described only the light to deep green mineral from
Alexander County, North Carolina, USA. Crystals from
this location are colored green by the presence
of chromium. Some argue that the name should only apply
to the green crystals from North Carolina containing
chromium. Others say it can be applied to any Spodumene
that is of any shade of yellow, yellowish green or green
from any location. Originally Hiddenite was defined
in 1892 by George Frederick Kunz (1856-1932),
a famous author and gemologist, as "always transparent, ranges from colorless
(rare) to a light yellow, into a yellowish green, then into a deep yellow
emerald green. Sometimes an entire crystal has a uniform green color, but
generally one end is yellow and the other green." These
days, the name is used to describe a wide variety of
Spodumene crystals and gems from several locations
and with a wide variety of colors from very pale yellow
(nearly colorless) to very pale yellowish green to
deep emerald green.
Hiddenite is strongly pleochroic, meaning
it has a color intensity difference when viewed from
different directions. It is a very difficult gem to
facet because of its strong pleochroism and easy, splintery cleavage.
Using
the loose definition of Hiddenite, the mineral is found
in several locations around the world including
Afghanistan, Minas Gerais, Brazil;
Xinjiang-Uygur, China; Ambatovita, Madagascar; Alto Ligonha District, Mozambique;
and Shigar, Pakistan.
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Hiddenite
gems for sale:
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have not photographed the Hiddenite gems. Please
check back soon.
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