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| Chemistry:
Na8Al6Si6O24(Cl2,S) | Discovered
in 1811;
IMA
status: Hackamnite, Not Valid; Sodalite, Valid Hackmanite
is named for Finnish geologist, Victor Hackman (1866-1941).
Sodalite
is named after its chemical composition containing Sodium
(Na). |
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Classification
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Mineral
Classification: |
Silicates |
Strunz 8th
Ed. ID:
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8/J.11-10 |
Nickel-Strunz 10th
Ed. ID:
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9.AC.05 |
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9 : SILICATES (Germanates) F : Tektosilicates without zeolitic
H2O B : Tektosilicates with additional anions
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Related
to: |
Sodalite
Group
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Crystal
Data
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Crystallography:
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Isometric
- Hextetrahedral |
Crystal
Habit:
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Crystals
rare, typically dodecahedra, to 10 cm; as embedded grains
or massive.
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Twinning:
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On
[111], common, forming pseudohexagonal prisms by elongation
along [111].
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Physical
Properties
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Cleavage: |
[110]
Poor
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Fracture: |
Uneven
to Conchoidal
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Tenacity:
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Brittle
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Hardness
(Mohs): |
5.5 - 6.0 |
Density:
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2.14 - 2.40 (g/cm3) |
Luminescence:
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Bright
red-orange cathodoluminescence and fluorescence under
LW and SW UV, with yellowish phosphorescence; may be
photochromic in magentas. |
Radioactivity:
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Not
Radioactive |
other: |
May
give of the odor of H2S on fracture. |
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Optical
Properties
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Color: |
Colorless,
White, Gray, Pink to
Violet, Lavender, Purple, pale Blue |
Transparency: |
Transparent
to Translucent |
Luster: |
Vitreous,
Greasy |
Refractive
Index: |
1.483
- 1.487 Isotropic |
Birefringence: |
0.000
Isotropic minerals have no birefringence |
Dispersion: |
Weak;
0.018 |
Pleochroism: |
None
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Occurances
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Geological
Setting: |
Formed
in nepheline syenites, phonolites, and related rock
types. In metasomatized calcareous rocks, and in cavities
in ejected volcanic blocks. |
Common
Associations: |
Nepheline,
Cancrinite, Titanian Andradite, Aegirine, Microcline,
Sanidine, Albite, Calcite, Fluorite, Ankerite, Barite. |
Type
Locality: |
Tawa valley, Kola Peninsula, Murmanskaja Oblast', Northern Region, Russia. |
Year
Discovered: |
1811 |
View
mineral photos: |
Hackmanite
Mineral Photos and Locations |
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More
Information
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Mindat.org
(Hackmanite) Mindat.org
(Sodalite) Webmineral.com
(Sodalite) |
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Hackmanite is an important variety of Sodalite and is a member of the Sodalite
group that also includes
Haüyne,
Tugtupite
and Lazurite. Sodalite is also
a member of the Feldspathoid
group of minerals that includes Cancrinite,
Lazurite, Leucite,
and Nepheline. Hackmanite
exhibits Tenebrescence.
This means it may turn shades of pink, violet or
purple when exposed to sunlight or shortwave
(SW) UV light and when removed from the light it gradually
fades back to white or pale yellow. This process is accelerated
by the use of shortwave UV light and the cycle is repeatable.
There
are many sources of Sodalite, but very few for gem quality
crystals of Hackmanite. Some of these are Koksha Valley, Badakhshan Province, Afghanistan;
Poudrette quarry, Mont Saint-Hilaire, Rouville County, Québec, Canada;
Svintsovyi Ruchei (Lead Creek), Kukisvumchorr Mt,
Khibiny Massif, Kola Peninsula, Murmanskaja Oblast', Northern Region, Russia
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Hackmanite
gems for sale:
We
have not photographed the Hackmanite gems. Please
check back soon.
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