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Strontianite (SrCO3) is an important raw material for the extraction of strontium. It is a rare carbonate mineral and one of only a few strontium minerals. It is a member of the aragonite group. Aragonite group members:〔 *aragonite CaCO3 *witherite BaCO3 *strontianite SrCO3 *cerussite PbCO3 The ideal formula of strontianite is SrCO3, with molar mass 147.63 g,〔 but calcium Ca can substitute for up to 27% of the strontium Sr cations, and barium Ba up to 3.3%.〔 The mineral was named in 1791 for the locality, Strontian, Argyllshire, Scotland, where the element strontium had been discovered the previous year.〔 Although good mineral specimens of strontianite are rare, strontium is a fairly common element, with abundance in the Earth's crust of 370 parts per million by weight, 87 parts per million by moles, much more common than copper with only 60 parts per million by weight, 19 by moles.〔http://www.chemicool.com/elements/strontium.html – retrieved 24/08/11〕 Strontium is never found free in nature. The principal strontium ores are celestine SrSO4 and strontianite SrCO3. The main commercial process for strontium metal production is reduction of strontium oxide with aluminium.〔 == Unit cell == Strontianite is an orthorhombic mineral, belonging to the most symmetrical class in this system, 2/m 2/m 2/m, whose general form is a rhombic dipyramid. The space group is Pmcn. There are four formula units per unit cell (Z = 4) and the unit cell parameters are a = 5.1 Å, b = 8.4 Å, c = 6.0 Å. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Strontianite」の詳細全文を読む スポンサード リンク
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