Celestine

This is a short overview. For the background — history, value over time and notable mines — see Celestine →

Strontium sulphate — a pale blue or water-clear mineral, and the world's principal ore of strontium. It was worked first for sugar-beet refining, then for the intense red flame its strontium salts give, which made it essential to fireworks, signal flares and tracer ammunition, and later for television glass, paint and ceramics.