Celestite Value, Price, and Jewelry Information

Custom cushion-cut celestite, 5.12 cts, 10.6 x 8.9 mm, Madagascar. © The Gem Trader. Used with permission.

Celestite

Soft, fragile, and hard to cut, celestite or celestine is seldom seen in gem collections. Large, clean faceted celestites are very rare. These gems are usually colorless or pale blue, but rare orange, green, yellow, and red shades have also been found.

Celestite Information

Data Value
Name Celestite
Crystallography Orthorhombic, Crystals common, usually tabular; also nodules, earthy, massive.
Refractive Index 1.622-1.635
Colors Colorless, white, gray, blue, green, yellow, orange, and red shades.
Luster Vitreous; pearly on cleavage.
Hardness 3-3.5
Fracture Uneven
Specific Gravity 3.97-4.00
Birefringence 0.009-0.012
Cleavage Perfect 1 direction, good 1 direction
Dispersion 0.014
Heat Sensitivity Yes
Luminescence Blue in SW. Blue or dull yellow in LW. May phosphoresce blue-white.
Luminescence Present Yes
Luminescence Type Fluorescent, Phosphorescent, UV-Long, UV-Short
Transparency Transparent
Absorption Spectrum Not diagnostic
Formula SrSO4
Pleochroism Weak, in shades of indigo blue, bluish green, and violet.
Optics a = 1.622 – 1.625; β = 1.624; γ = 1.631 -1.635. Biaxial (+), 2V = 50°
Optic Sign Biaxial +
Etymology From the Latin coelestis for “celestial,” in allusion to the delicate and lovely pale blue color often displayed by this mineral.
Occurrence Celestite occurs in sedimentary rocks, especially limestones; it is also found in hydrothermal vein deposits, sometimes in igneous rocks.
Inclusions Single phase, liquid inclusions; partially healed fractures.
celestites in geode

Celestites in a geode, Sakoany deposit, Katsepy Commune, Mitsinjo District, Boeny Region, Mahajanga Province, Madagascar. © Rob Lavinsky, www.iRocks.com. Used with permission.

Comments

The minerals barite and celestite form a series. Baryte lies at the barium (Ba) end; celestite at the strontium (Sr) end. This mineral is a major source of strontium.

While transparent crystals aren’t rare per se, facetable gem-quality material is quite rare. Faceted gems show little dispersion.

celestine green crystal - Austin, Texas

Celestine crystal (celestite), Bull Creek, near Austin, Travis County, Texas, USA. © Rob Lavinsky, www.iRocks.com. Used with permission.

Identifying Characteristics

Gems from Madagascar have refractive indices as follows: a = 1.619; γ = 1.631.

Synthetics

None known.

Enhancements

Blue gems may fade because of heat or light, but irradiation may restore the color.

Sources

Canada produces rare orange crystals. Tsumeb, Namibia also yields gem-quality material.

  • United States: California; Colorado; Strontian Islands, Lake Erie, Michigan (gemmy material); Chittenango Falls, New York; Clay Center, Put-in-Bay, Ohio; Lampasas, Texas (gemmy blue material).
  • Austria; Egypt; Bristol, England; France; Germany; Italy; Madagascar; San Luis Potosi, Mexico; Russia; Girgenti, Sicily; Switzerland; Tunisia.
celestite - Canada faceted gem

Celestite: Canada (1.5). Photo © Joel E. Arem, PhD, FGA. Used with permission.

Stone Sizes

Celestite gems, usually colorless or pale blue, typically weigh under three carats and often receive step cuts. However, some gems are known in the 30-carat range. Large, transparent crystals may be found and cut.

Put-in-Bay, Ohio boasts the Crystal Cave, “the world’s largest geode.” Converted into a cave, the 35′ wide geode contains celestite crystals up to 18” across.

  • Devonian Group (Calgary, Alberta, Canada): 20.1 cts (blue, Madagascar).
  • National Museums of Canada (Ottawa, Ontario): 3.11 cts (orange step cut, Ontario, Canada).
  • Private collection: 2.98 cts (blue, New York)
celestite crystals - Crystal Cave, Ohio

Celestite crystals, Crystal Cave, Put-in-Bay, Ohio. Photo by James St. John. Licensed under CC By 2.0.

Care

Due to its softness, perfect cleavage, and light sensitivity, this gem makes a better collector’s item than a jewelry piece. Celestites also have great heat sensitivity. Since jeweler’s torches can easily exceed 200° C (392° F) and cause the stone’s colors to fade, be wary if you take a jewelry piece to be repaired. Consult our gemstone jewelry cleaning guide for more recommendations.

celestite - Madagascar faceted gem

Celestite: Madagascar (16.3). Photo © Joel E. Arem, PhD, FGA. Used with permission.

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