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| Glauberite
is named in allusion to Glauber’s Salt (Na2SO4),
the synthetic equivalent of the dominant chemical component,
named for Johann Rudolf Glauber (1604–1668), German
alchemist.
| Discovered
in 1808;
IMA
status: Valid (pre-IMA; Grandfathered). |
|
Chemistry
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|
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Chemical
Formula: |
Na2Ca(SO4)2 |
|
Sodium
Calcium Sulfate |
Molecular
Weight: |
278.18 gm |
Composition: |
Sodium |
16.53 %
|
Na
|
22.28 %
|
Na2O
|
Calcium |
14.41 %
|
Ca
|
20.16 %
|
CaO
|
Sulphur |
23.05 % |
S |
57.56 % |
SO3 |
Oxygen |
46.01 % |
O |
|
|
|
100.00 % |
|
100.00 % |
= TOTAL OXIDE |
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Classification
|
|
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Mineral
Classification: |
Sulfates
|
Strunz 8th
Ed. ID:
|
6/A.08-40
|
Nickel-Strunz 10th
Ed. ID:
|
7.AD.25 |
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7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates) A : Sulfates (selenates, etc.) without additional anions, without H2O D : With only large cations
|
Related
to: |
n/a
|
Synonyms: |
Glauber's
Salt
|
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Crystal
Data
|
|
|
Crystallography:
|
Monoclinic
- Prismatic
|
Crystal
Habit:
|
Crystals,
to 10 cm, tabular on {001}, prismatic along [101] with
dominant {111} or along [001] with dominant {110}, or
dipyramidal with dominant {111}, {110}; {001} and {111}
may be striated k mutual intersections, yielding steplike
terminations.
|
Twinning:
|
None
|
|
|
Physical
Properties
|
|
|
Cleavage: |
[001]
Perfect, [110] Imperfect
|
Fracture: |
Conchoidal
|
Tenacity:
|
Brittle
|
Moh's
Hardness: |
2.5
- 3.0
|
Density:
|
2.75
- 2.85 (g/cm3)
|
Luminescence:
|
None |
Radioactivity:
|
Not
Radioactive
|
Other: |
Slightly
saline taste; powdery surface alteration in humid environments,
leaching Na2SO4
and leaving gypsum. Very slightly soluble in water.
|
|
|
Optical
Properties
|
|
|
Color: |
Gray,
pale Yellow, Colorless; Colorless in transmitted light
|
Transparency: |
Transparent
to Translucent
|
Luster: |
Vitreous
to
Waxy; Pearly on {001} cleavage surfaces
|
Refractive
Index: |
1.507
- 1.536 Biaxial ( - )
|
Birefringence: |
0.0220
|
Dispersion: |
Strong;
r > v
|
Pleochroism: |
X
= colorless; Y = colorless
|
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|
Occurances
|
|
|
Geological
Setting: |
A
common constituent of continental and marine evaporite
deposits; as sublimates around fumaroles; in mineral-filled
cavities in basaltic lava; in nitrate deposits in arid
climates. |
Common
Associations: |
Anhydrite,
Gypsum, Halite, Mirabilite, Polyhalite, Thénardite (evaporites);
Thénardite, Sassolite (fumaroles); Blödite, Thénardite
(nitrate deposits).
|
Co-type
Localities: |
El Castellar mine, Villarrubia de Santiago, Ocaña, Toledo, Castile-La Mancha, Spain Los Castilletes mine, Villarrubia de Santiago, Ocaña, Toledo, Castile-La Mancha, Spain |
Year
Discovered: |
1808 |
View
mineral photos: |
Glauberite
Mineral Photos and Locations |
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More
Information
|
|
|
|
Mindat.org Webmineral.com
|
|
|
Glauberite is named for the salt that helps compose its chemistry called "Glauber's salt" which
is named after German alchemist Johann Rudolf Glauber (1604–1668).
It is a mineral that forms in saline environments with other evaporite minerals such as halite, Gypsum,
Calcite and
Thénardite.Glauberite is a relatively rare mineral and an extremely rare gem. Glauberite
gems are curiosities for collectors of the very
rare and unusual.
Glauberite
is often pseudomorphed or cast by other minerals.
Pseudomorph means "false shape" and occurs
when a mineral is replaced by another mineral at such
a very slow rate, essentially atom by atom, that no
deterioration of the original shape of the crystal occurs.
The resulting crystal retains the shape of the original
mineral crystal but has the composition of the new mineral.
A cast occurs when other minerals grow over an existing
crystal then the original crystal completely dissolves,
leaving a cast of the shape of the original crystal.
The crystal habit, or shape, of a Glauberite crystal
is unique enough that its pseudomorphs and casts can
often be identified as being from a Glauberite crystal.
Glauberite is soluble in water which is why it often
creates casts.
Notable occurrences of
Glauberite include Saline Valley, Inyo County and Searles
Lake, San Bernardino County, California; Great Salt Lake, Utah, Texas, New
Mexico and Verde Valley, Arizona, USA;
Strassfurt, Germany; Russia; Kenya; Chile; Toledo, Spain; Salzburg,
Austria; France; Canada; Sicily and India.
Pseudomorphs and casts come from many of the previously mentioned
localities and from Paterson and Great Notch, New Jersey, USA.
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Glauberite
gems for sale:
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