Celestine SrSO

The strontium content in the lithosphere is ca. 370 mg/kg (i.e., ppm wt.), but, owing to its chemical reactivity, the metal does not occur free in nature. The chief strontium containing minerals are the sulfate celestite or celestine [SrSO, orthorhombic] and the carbonate strontianite [SrCOj, orthorhombic], but strontium traces can also be found in calcium and barium-containing minerals. Nevertheless, strontium minerals rarely concentrate in large ore deposits, and the chief ore is only represented by celestite because there are no known economically workable strontianite deposits. However, strontium occurs widely dispersed in seawater and in igneous rocks as a minor constituent of rock-forming minerals. 

Manufacture. Strontium carbonate occurs naturally as a strontium ore, but the production is not large. Celestine(consisting mainly of SrSO and containing Ca and Ba) is heated with sodium carbonate to form a melt, and the product is then washed with water to remove the strontium sulphate. 

Definition Occurs in nature as the mineral celestine or celestite Empirical OjSSr Formula SrSO,... 

Celestite [7759-02-6] (syiL, celestine) [from the Latm, caelestis, meaning celestial] (ICSD 28055 and PDF 5-593) SrSO, M= 183.6836 47.70 wt.% Sr 17.46 wt.%S 34.84 wt.% 0 Coordinence Sr(6), S(4) (Sulfetes, diromates, molybdates, and tungstates) Orthorhombic a = 835.9 pm b= 535.2 pm c= 686.6 pm (Z = 4) P.G. mmm S.G. P2,nma Barite type Biaxial (-t) a= 1.622 1.624 r= 1.631 S= 0.009 2y=5i Dispersion moderate 3-3.5 3970 Habit tabular, radiated fibrous, crystalline, massive, granular. Color colorless, bluish white, yellowish white, or reddish white. Diaphaneity transparent to translucent. Luster vitreous (ie., glassy). Streak white. Qeavage (001) perfect, (210) good. Fracture uneven to conchoidal, brittle. Chemical decomposed at 1607 C Occurrence sedimentary rocks. 

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