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, or | luster = Vitreous | opticalprop = Biaxial (+) | refractive = nα = 1.730 nβ = 1.758 nγ = 1.838 | birefringence = δ = 0.108 | dispersion = relatively weak | pleochroism = Visible shades of blue | 2V = Measured: 68°, calculated: 64° | streak = Light blue | gravity = 3.773 (measured), 3.78 (calculated) | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = Transparent to translucent | references = 〔(Handbook of Mineralogy )〕〔(Mindat.org )〕〔(Webmineral.com Webmineral Data )〕 }} Azurite is a soft, deep blue copper mineral produced by weathering of copper ore deposits. It is also known as Chessylite after the type locality at Chessy-les-Mines near Lyon, France.〔 The mineral, a carbonate, has been known since ancient times, and was mentioned in Pliny the Elder's Natural History under the Greek name ''kuanos'' (κυανός: "deep blue," root of English ''cyan'') and the Latin name ''caeruleum''.〔(The Ancient Library: Smith, Dictionary of Greek and Roman Antiquities, p.321, right col., under ''BLUE'' )〕 The blue of azurite is exceptionally deep and clear, and for that reason the mineral has tended to be associated since antiquity with the deep blue color of low-humidity desert and winter skies. The modern English name of the mineral reflects this association, since both ''azurite'' and ''azure'' are derived via Arabic from the Persian ''lazhward'' (لاژورد), an area known for its deposits of another deep blue stone, lapis lazuli ("stone of azure"). ==Mineralogy== Azurite is one of the two basic copper(II) carbonate minerals, the other being bright green malachite. Simple copper carbonate (CuCO3) is not known to exist in nature. Azurite has the formula Cu3(CO3)2(OH)2, with the copper(II) cations linked to two different anions, carbonate and hydroxide. Small crystals of azurite can be produced by rapidly stirring a few drops of copper sulfate solution into a saturated solution of sodium carbonate and allowing the solution to stand overnight. Azurite crystals are monoclinic, and when large enough to be seen they appear as dark blue prismatic crystals.〔〔〔Hurlbut, Cornelius S.; Klein, Cornelis, 1985, ''Manual of Mineralogy'', 20th ed., Wiley, ISBN 978-0-471-00042-6〕 Azurite specimens are typically massive to nodular, and are often stalactitic in form. Specimens tend to lighten in color over time due to weathering of the specimen surface into malachite. Azurite is soft, with a Mohs hardness of only 3.5 to 4. The specific gravity of azurite is 3.77 to 3.89. Azurite is destroyed by heat, losing carbon dioxide and water to form black, powdery copper(II) oxide. Characteristic of a carbonate, specimens effervesce upon treatment with hydrochloric acid. 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「azurite」の詳細全文を読む スポンサード リンク
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