Celestine

Big Photo

Madagascar
20.50 carats
© Rarestone.com

Celestine is named after Latin "caelestis" - of the sky, alluding to the sky-blue colour commonly exhibited by its crystals.

Celestine is usually colourless or pale blue, but orange (Ontario, Canada), brown, yellow and greenish material has been reported.

It occurs as tabular and prismatic crystals, and also in compact massive and fibrous forms or as numerous crystals lining geodes. The geode has crystals as 18 inches wide (46 cm) across, estimated weight up to 300 pounds (135 kg) each.

Perfect cleavage and brittleness make Celestine difficult to facet. Cut stones rarely exceed 10 carats.



Celestine Gemstones by Colour

This table shows the variety of hues this gemstone can be found in. Click on a photo for more information.
 
 

Celestine Gemstones by Size

This table shows distribution of Celestine gemstone sizes that are listed on this site. This can give a good indication as to the general availability of this gemstone in different sizes.
Contributed photos
Lightest:4.55 cts
Heaviest:20.50 cts
Average:12.53 cts
Total photos:2
Do you have a larger Celestine? Why not upload a photo?
4.55ct to 6.15ct6.15ct to 7.74ct7.74ct to 9.34ct9.34ct to 10.93ct10.93ct to 12.53ct12.53ct to 14.12ct14.12ct to 15.72ct15.72ct to 17.31ct17.31ct to 18.91ct18.91ct to 20.50ct
General Information
Other Names/Trade Names:
Chemical Formula
SrSO
 
4
Michael O’Donoghue, Gems, Sixth Edition (2006)
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Photos of natural/un-cut material from mindat.org
Celestine Treatments
Celestite, SrSO4, also called celestine, as well as the closely related ,materials anhydrite, CaSO4, also called vulpinite (Webster, p. 298), and barite, BaSO4, are soft sulfates which occur at times with attractive violet or blue colors. Heating to as little as 200°C causes these colors to fade, as also sometimes happens on exposure to light. Irradiation restores or produces the blue or violet color, sometimes in a banded form; the color may be stable to light or may fade, depending on the nature of the material (Przibram and Caffyn, 1956; Pough, 1957). In celestite there are several color centers involved, including SO-3, SO-2 and O-, all stabilized by a potassium impurity (Bernstein, 1979) – Nassau (1984)
Physical Properties of Celestine
Mohs Hardness3 to 3.5
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
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Specific Gravity3.90 to 4.00
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
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TenacityBrittle
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010) Very brittle
Cleavage QualityPerfect
Arthur Thomas, Gemstones (2009)
FractureUneven
Arthur Thomas, Gemstones (2009)
Heat SensitivitySensitive to heat
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
Optical Properties of Celestine
Refractive Index1.619 to 1.635
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
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Optical CharacterBiaxial/+
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
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Birefringence0.004 to 0.012
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
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PleochroismWeakly trichroic
Arthur Thomas, Gemstones (2009)
DispersionNil
Arthur Thomas, Gemstones (2009)
Colour
Colour (General)Bluish-white, colourless, seldom reddish, green
Walter Schumann, Gemstones of the world (2001)
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TransparencyTransparent
Michael O’Donoghue, Gems, Sixth Edition (2006)
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LustreVitreous
Walter Schumann, Gemstones of the world (2001)
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Fluorescence & other light emissions
Fluorescence (General)Inert to weak fluorescence of body color (possible phosphorescence)
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
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Crystallography of Celestine
Crystal SystemOrthorhombic
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
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HabitTabular
Michael O’Donoghue, Gems, Sixth Edition (2006)
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Geological Environment
Where found:The origin of celestine is chiefly sedimentary. It occurs as cavity or
fissure fillings, particularly in limestones and in hydrothermal veins.
Michael O’Donoghue, Gems, Sixth Edition (2006)
Inclusions in Celestine
Liquid inclusions, partially healed fractures - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 5
Further Information
Mineral information:Celestine information at mindat.org
Significant Gem Localities
Namibia
 
  • Oshikoto Region
    • Tsumeb
Gems, Sixth Edition, Michael O’Donoghue, 2006, p. 396
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