Celestine (also called Celestite)
Current inventory:  1 gem
 

  
Celestine is named from the Latin coelestis meaning celestial refering to the beautiful pale blue color of some specimens.

Discovered in 1791;   IMA status:  Valid (pre-IMA; Grandfathered)

Chemistry

Chemical Formula:

SrSO₄

Strontium Sulfate

Molecular Weight:

183.68 gm

Composition:

Stontium

47.70 %

Sr

56.41 %

SrO

Sulfur

17.46 %

S

43.59 %

SO₃

Oxygen

34.84 %

O

100.00 %

100.00 %

= TOTAL OXIDE

Classification

Mineral Classification:

Sulfates

Strunz 8th Ed. ID:

6/A.09-10

Nickel-Strunz 10th Ed. ID:

7.DG.15

7 : SULFATES (selenates, tellurates, chromates, molybdates, wolframates)
A : Sulfates (selenates, etc.) without additional anions, without H₂O
D : With only large cations

Related to:

Baryte Group. Baryte-Celestine Series. The strontium analogue of Baryte.

Members of Group:

Baryte Group: Anglesite, Baryte, Celestine, Hashemite.

Varieties:

Barian Celestine, Barytosulfate of Strontian, Calciocelestine

Synonyms:

Celestite, Coelestine, Eschwegite (of Lévy), Sicilianite

Crystal Data

Crystallography:

Orthorhombic - Dipyramidal

Crystal Habit:

Well-formed crystals common, typically thin to thick tabular and elongated yielding lath-like forms; or elongated to 45 cm with equant cross section; also pyramidal, commonly striated. Fibrous veinlets or nodules with parallel or radiated fiber structure; massive granular; lamellar, earthy, rare.

Twinning:

Reported on {210}, {101} and other planes.

Physical Properties

Cleavage:

Perfect on {001} and {210}, Poor on {010}

Fracture:

Irregular to Uneven

Tenacity:

Brittle

Moh's Hardness:

3.0 - 3.5

Density:

3.96 - 3.98 (g/cm³)

Luminescence:

May be Fluorescent. Yellow, Bluish White under SW UV and LW UV

Radioactivity:

Not Radioactive

Other:

Very slightly soluble in water. Slowly soluble in hot concentrated acids or alkali carbonate solutions.

Optical Properties

Color:

Colorless, shades of Light Blue, White, Reddish, Greenish, Brownish, Greyish

Transparency:

Transparent to Translucent

Luster:

Vitreous to Pearly

Refractive Index:

1.619 - 1.632  Biaxial ( + )

Birefringence:

0.009 - 0.010

Dispersion:

0.014; Moderate; r < v

Pleochroism:

Weak; Blue colored material: shades of Indigo and Lavender-Blue, Bluish Green or Violet

Occurances

Geological Setting:

Occurs mainly in sedimentary rocks such as bedded deposits of gypsum and halite; also in bedded limestone and dolomite, in cavities.

Common Associations:

Analcime, Anhydrite, Calcite, Celadonite (mafic volcanoclastics), Dolomite, Fluorite (cavities in carbonate rocks), Gypsum, Natrolite, Hydroxyapophyllite, Strontianite, Sulfur (bedded evaporites)

Common Impurities:

None

Type Locality:

Bell's Mill, Bellwood, Blair County, Pennsylvania, USA

Year Discovered:

1791

View mineral photos:

Celestine Mineral Photos and Locations

More Information

Mindat.org
Webmineral.com

Celestine (also called Celestite) is a rare collector's gem that is found as colorless, pale blue or rarely orange. It is a soft and fragile gem that is very difficult to cut and not recommended for jewelry. Celestine is a unusual Strontium and Sulfur mineral that is a member of the Barite mineral group that also includes Anglesite and Barite. Celestine (SrSO4) is the strontium analog of Barite (BaSO4). Celestine contains strontium (Sr) in place of Barite's barium (Ba). Both have the same structure and can form very similar crystals.

Current sources are Rochefort, Namur Province, Belgium; Sakoany Mine, Sofia Region, Mahajanga Province, Madagascar; Chihuahua, Mexico; Hunan Province, China; Andalusia, Spain; and in the USA at Maybee, Michigan; Chittenango Falls, New York; Clay Center, Ohio.
 

  
Celestine gems for sale: