Mineral Species: Celestine

Chemical Formula: SrSO4

Chemical Name: Strontium Sulphate

Mineral Class: Sulphate

Mineral Notes: Celestine occurs as a sedimentary deposit, frequently associated with rock-salt, Gypsum and Clay minerals. The name is derived from "celeste" after the blue colour resembling the sky, which it closely resembles. The mineral is the most common Strontium mineral and the main ore of the metal. Strontium compounds burn with a crimson flame and are used in the manufacture of flares, fuses and fireworks.

Description: Numerous plate-like crystals of Celestine. These are mostly tabular prisms, but some show pseudo-hexagonal form due to twinning. Unusually, the mineral is almost white and the crystals show considerable transparency. A strong glassy luster.

Location: Yate, Gloucestershire, England.