Strontium sulfate (SrSO4) is the sulfate salt of strontium. It is a white crystalline powder and occurs in nature as the mineral celestine. It is poorly soluble in water to the extent of 1 part in 8,800. It is more soluble in dilute HCl and nitric acid and appreciably soluble in alkali chloride solutions (e.g. sodium chloride).
3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||183.68 g/mol|
|Appearance||white orthorhombic crystals|
|Melting point||1,606 °C (2,923 °F; 1,879 K)|
|0.0135 g/100 mL (25 °C) |
0.014 g/100 mL (30 °C)
Solubility product (Ksp)
|3.44 x 10−7|
|Solubility||insoluble in ethanol, alkalis |
slightly soluble in acids
Refractive index (nD)
|Pnma, No. 62|
Std enthalpy of
|NFPA 704 (fire diamond)|
|Safety data sheet (SDS)||External MSDS data|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
(what is ?)
Strontium sulfate is a polymeric material, isostructural with barium sulfate. Crystallized strontium sulfate is utilized by a small group of radiolarian protozoa, called the Acantharea, as a main constituent of their skeleton.
Strontium sulfate is of interest as a naturally occurring precursor to other strontium compounds, which are more useful. In industry it is converted to the carbonate for use as ceramic precursor and the nitrate for use in pyrotechnics.
The low aqueous solubility of strontium sulfate can lead to scale formation in processes where these ions meet. For example, it can form on surfaces of equipment in underground oil wells depending on the groundwater conditions.