STRONTIANITE wih CALCITE (miniature)

Strontianite (SrCO3) serves as a crucial raw material for strontium extraction, classified as a rare carbonate mineral and one of the few known strontium minerals, belonging to the aragonite group. The ideal chemical formula for strontianite is SrCO3, with a molar mass of 147.63 g, although calcium (Ca) can replace up to 27% of the strontium (Sr) cations, and barium (Ba) can substitute for up to 3.3%. Discovered in 1791 in Strontian, Argyllshire, Scotland, where strontium was identified the year prior, strontianite specimens are uncommon. However, strontium itself is relatively abundant in the Earth's crust, occurring at 370 parts per million by weight and 87 parts per million by moles, making it more prevalent than copper. Strontium is never found in its free form in nature, with celestine (SrSO4) and strontianite (SrCO3) being the primary ores. The predominant method for producing strontium metal involves reducing strontium oxide with aluminum. Structurally, strontianite is an orthorhombic mineral, characterized by its rhombic dipyramid shape and belonging to the most symmetrical class of this system, 2/m 2/m 2/m.