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| Searlesite
is named after John W. Searles, California pioneer,
who put down the deep well from which type material
was extracted. The type locality, Searles Lake is also
named after him.
| Discovered
in 1914;
IMA
status: Valid (pre-IMA; Grandfathered) |
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Chemistry
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Chemical
Formula: |
NaBSi2O5(OH)2
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Sodium
Boron Silicate Hydroxide |
Molecular
Weight: |
203.98 gm |
Composition: |
Sodium |
11.27 % |
Na |
15.19 % |
Na2O |
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Silicon |
27.54 % |
Si |
58.91 % |
SiO2 |
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Boron |
5.30 % |
B |
17.06 % |
B2O3 |
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Hydrogen |
0.99 % |
H |
8.83 % |
H2O |
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Oxygen |
54.90 % |
O |
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|
100.00 % |
|
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/G.05-10
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Nickel-Strunz 10th
Ed. ID:
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9.EF.15
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9 : SILICATES (Germanates) E : Phyllosilicates F : Single nets with 6-membered rings, connected by M[4], M[8], etc.
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Crystal
Data
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Crystallography:
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Monoclinic
- Sphenoidal
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Crystal
Habit:
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Flat
crystals, to 17 cm, occur along bedding planes. Commonly
as spherulitic aggregates of radiating acicular to prismatic
crystals; as massive granular aggregates.
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Twinning:
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None
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Physical
Properties
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Cleavage: |
Perfect
on {100}; imperfect on {102}, {010}
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Fracture: |
Fibrous
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Tenacity:
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Brittle,
Fibrous
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Moh's
Hardness: |
1.0
- 2.0
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Density:
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2.44
- 2.46 (g/cm3)
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Luminescence:
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Fluorescent; SW UV
= blue green or green, LW UV = orange |
Radioactivity:
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Not
Radioactive
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Other: |
Piezoelectric
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Optical
Properties
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Color: |
Colorless,
White, light Brown
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Transparency: |
Translucent to
Transparent
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Luster: |
Vitreous,
slightly
pearly on cleavage surfaces
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Refractive
Index: |
1.515
- 1.535 Biaxial ( - )
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Birefringence: |
0.0110
- 0.0200
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Dispersion: |
None
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Pleochroism: |
None
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Occurances
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Geological
Setting: |
Commonly
interbedded with oil shales or marls (Green River Formation,
USA); in boron-bearing evaporite deposits (California,
USA); rarely in vugs in phonolite (Point of Rocks, New
Mexico, USA). |
Common
Associations: |
Shortite,
Trona, Pyrite (Green River Formation, USA); "Opal"
(Cave Springs Wash, Nevada, USA) |
Common
Impurities: |
Al,Fe,Mg,H2O
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Type
Locality: |
Searles Lake, San Bernardino County, California, USA
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Year
Discovered: |
1914
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View
mineral photos: |
Searlesite
Mineral Photos and Locations |
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More
Information
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Mindat.org Webmineral.com
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Searlesite
is a rare silicate mineral that is rarely available
faceted due to its soft and fibrous nature. It is not
an attractive gem but one that is for collectors of
the very unusual. Searlesite is a Piezoelectric mineral,
meaning that it has the ability to generate a voltage in response to applied mechanical
stress. Relatively large crystals are usually flat and fibrous and occur along bedding planes.
Tiny transparent prismatic
crystals are much too small for faceting.
Searlesite
can be found in the USA, at Searles Lake, San Bernardino
County, in the Kramer borate deposit, Kern County, and
at Lake Tecopa, Inyo County, California; widespread
in the Green River Formation of Utah and Wyoming; from
Cave Springs Wash, Silver Peak Range, Esmeralda County,
Nevada; and at Point of Rocks, Colfax County, New Mexico.
In Canada, at Mont Saint-Hilaire, Quebec. From Kremna,
near Tito Uzice; Lopare; and near Bela Stena, Yugoslavia.
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Searlesite
gems for sale:
We
have not photographed our Searlesite gems. Please
check back soon.
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