Celestite

Celestite known gemmologicaly as Celestine is a mineral consisting of strontium sulfate (SrSO₄) and is part of the Baryte-Celestine Series (Ba,Sr)SO₄ and is a member of the Baryte group with a Orthorhombic crystal system. The mineral is named for its occasional delicate blue color. Celestine and the carbonate mineral strontianite are the principal sources of the element strontium, commonly used in fireworks and in various metal alloys.