Strontianit

Strontianite is a naturally occurring mineral, a carbonate of strontium with the chemical formula SrCO3. It belongs to the aragonite group of minerals and crystallizes in the orthorhombic system. Its name is derived from the village of Strontian in Argyll, Scotland, where it was first discovered. Strontianite is typically found in sedimentary rocks such as limestones and sandstones, often associated with other strontium minerals like celestine. It can also occur in hydrothermal veins and as a secondary mineral in igneous rocks.

The mineral is characterized by its prismatic or acicular crystal habit, though it can also be found in massive or granular forms. Pure strontianite is colorless, but impurities can impart various colors, including white, gray, yellow, and greenish hues. It possesses a vitreous to resinous luster and a hardness of 3 to 3.5 on the Mohs scale. Its specific gravity ranges from 3.6 to 3.8. Strontianite is relatively soft and can be scratched by a knife.

While strontianite is the primary ore of strontium, it is less common than celestine (strontium sulfate). It has historically been used as a source for strontium compounds, which find applications in pyrotechnics to produce red colors, in glass manufacturing, and in the production of some specialized alloys. Despite its historical importance, the mining of strontianite has largely been supplanted by the extraction of strontium from celestine due to the latter's greater abundance and ease of processing.