Fluorite (also called fluorspar) is the mineral form of calcium fluoride, CaF2. It belongs to the halide minerals. It crystallizes in isometric cubic habit, although octahedral and more complex isometric forms are not uncommon.
Fluorite is a colorful mineral, both in visible and ultraviolet light, and the stone has ornamental and lapidary uses. Industrially, fluorite is used as a flux for smelting, and in the production of certain glasses and enamels. The purest grades of fluorite are a source of fluoride for hydrofluoric acid manufacture, which is the intermediate source of most fluorine-containing fine chemicals. Optically clear transparent fluorite lenses have low dispersion, so lenses made from it exhibit less chromatic aberration, making them valuable in microscopes and telescopes. Fluorite optics are also usable in the far-ultraviolet range, where conventional glasses are too absorbent for use.
==History and etymology==
Fluorite derives from the Latin noun ''fluo'', meaning a stream or flow of water. In verb form this was ''fluor'' or ''fluere'', meaning ''to flow''. The mineral is used as a flux in iron smelting to decrease the viscosity of slags. The melting point of calcium fluoride is 1676 K. The term flux comes from the Latin noun ''fluxus'', a wash or current of water. The mineral fluorite was originally termed fluorospar and was first discussed in print in a 1530 work ''Bermannus, sive de re metallica dialogus'' (or a dialogue about the nature of metals ), by Georgius Agricola, as a mineral noted for its usefulness as a flux.〔(【引用サイトリンク】publisher=Fluoride History )〕 Agricola, a German scientist with expertise in philology, mining, and metallurgy, named fluorspar as a Neo Latinization of the German ''Flussspat'' from ''Fluß'' (stream, river) and "Spat" (meaning a nonmetallic mineral akin to gypsum, spærstān, ''spear stone'', referring to its crystalline projections).
In 1852, fluorite gave its name to the phenomenon of fluorescence, which is prominent in fluorites from certain locations, due to certain impurities in the crystal. Fluorite also gave the name to its constitutive element fluorine.〔(Fluorite ). Mindat.org〕 Presently, the word "fluorspar" is most commonly used for fluorite as the industrial and chemical commodity, while "fluorite" is used mineralogically and in most other senses.
抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』
| 翻訳と辞書 : 翻訳のためのインターネットリソース|
Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.