柯石英

柯石英（英语：Coesite）是二氧化硅 SiO2 的一种形式（多晶型物），当对石英施加非常高的压力（2-3 吉帕斯卡）和中等高温（700°C，1,300°F）时形成。柯石英首先由诺顿公司的化学家 Loring Coes Jr. 于 1953 年合成。^[1].

产地

1960 年，Edward C. T. Chao 与Eugene Shoemaker在美国亚利桑那州巴林杰（英语：Barringer）陨石坑^[2] 找到了自然形成的柯石英，这证明该陨石坑一定是由撞击形成的。此后若柯石英在未变质岩石中找到，就证明为是陨石撞击或原子弹爆炸的证据。

在变质岩中，柯石英最初被发现是从地幔来的榴辉岩中的捕虏岩。被上升的岩浆携带到地面。在金伯利岩（英语：kimberlite）中这类捕虏岩很多^[3]。柯石英是属高压矿物，代表超高压变质作用的最佳指标矿物之一^[4]。这种超高压变质岩通常在隐没带造成。当地壳岩石被带到 70 公里（43 英里）或更深的深度。就能造成柯石英。柯石英是在高于约 2.5 GPa (25 kbar) 的压力和高于约 700 °C 的温度下形成的。相对应于地球约 70 公里的深度。当含柯石英的岩石被抬升到地表时，柯石英颗粒的表面会转换成石英。能对颗粒内部施压，进而保护颗粒内部，在减压下不稳定的柯石英。这就形成柯石英包裹体，而周边石英具有多晶型的特征。

很多世界各地的超高压变质岩中发现柯石英，包括意大利西部阿尔卑斯山的多拉迈拉（英语：Dora Maira）^[4]，德国的厄尔士山脉（英语：Erzgebirge）^[5]. 南极洲的兰特曼山脉（英语：Lanterman Range）^[6]，哈萨克斯坦的科克切塔夫地块（英语：Kokchetav Massif）^[7]，挪威西部片麻岩地区，^[8]，中国东部大别山山脉，^[9]，巴基斯坦东部喜马拉雅山脉，^[10]和佛蒙特州Vermont 阿巴拉契亚山脉Appalachian Mountains。^[11]。

结晶构造

柯石英是一种四面体中每个硅原子被四个氧原子包围的网状硅酸盐。然后每个氧原子与两个Si原子形成框架。在单位晶体中，硅原子有两个不同的位置而氧原子有五个不同的位置。尽管单位晶体在形状上接近于六边形，但它本质上是单斜晶体。柯石英的晶体结构与长石相似，这种结构在石英的稳定环境内是亚稳定状态的，柯石英会变回石英，随之体积会增加。这种变质在地球表面的低温下进行得非常缓慢^[12]。

参见

以人名命名的矿物列表

参考文献

^ Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C. (eds.). "Coesite" (PDF). Handbook of Mineralogy. Vol. II (Silica, Silicates). Chantilly, VA, US: Mineralogical Society of America. ISBN 0962209716. Retrieved December 5, 2011
^ Chao, E. C. T.; Shoemaker, E. M.; Madsen, B. M. (1960). "First Natural Occurrence of Coesite". Science. 132 (3421): 220–2. Bibcode:1960Sci...132..220C. doi:10.1126/science.132.3421.220. PMID 17748937. S2CID 45197811
^ Smyth, Joseph R.; Hatton, C.J. (1977). "A coesite-sanidine grospydite from the Roberts Victor kimberlite". Earth and Planetary Science Letters. 34 (2): 284. Bibcode:1977E&PSL..34..284S. doi:10.1016/0012-821X(77)90012-7
^ ^4.0 ^4.1 Chopin, Christian (1984). "Coesite and pure pyrope in high-grade blueschists of the Western Alps: a first record and some consequences". Contributions to Mineralogy and Petrology. 86 (2): 107–118. Bibcode:1984CoMP...86..107C. doi:10.1007/BF00381838. S2CID 128818052
^ Massonne, H.-J. (2001). "First find of coesite in the ultrahigh-pressure metamorphic area of the central Erzgebirge, Germany". European Journal of Mineralogy. 13 (3): 565–570. Bibcode:2001EJMin..13..565M. doi:10.1127/0935-1221/2001/0013-0565
^ Ghiribelli, B.; Frezzotti, M.L. & Palmeri, R. (2002). "Coesite in eclogites of the Lanterman Range (Antarctica): Evidence from textural and Raman studies". European Journal of Mineralogy. 14 (2): 355–360. Bibcode:2002EJMin..14..355G. doi:10.1127/0935-1221/2002/0014-0355
^ Korsakov, A.V.; Shatskiy, V. S. & Sobolev N.V. (1998). "Первая находка коэсита в эклогитах Кокчетавского массива (First occurrence of coesite in eclogites from the Kokchetav Massif)". Doklady Earth Sciences. 359: 77–81
^ Smith, D.C. (1984). "Coesite in clinopyroxene in the Caledonides and its implications for geodynamics". Nature. 310 (5979): 641–644. Bibcode:1984Natur.310..641S. doi:10.1038/310641a0. S2CID 4330257
^ Schertl, H.-P.; Okay, A.I. (1994). "A coesite inclusion in dolomite in Dabie Shan, China: petrological and rheological significance". Eur. J. Mineral. 6 (6): 995–1000. Bibcode:1994EJMin...6..995S. doi:10.1127/ejm/6/6/0995
^ O'Brien, P.J., N. Zotov, R. Law, M.A. Khan and M.Q. Jan (2001). "Coesite in Himalayan eclogite and implications for models of India-Asia collision". Geology. 29 (5): 435–438. Bibcode:2001Geo....29..435O. doi:10.1130/0091-7613(2001)029<0435:CIHEAI>2.0.CO;2
^ Joseph Gonzalez, Suzanne Baldwin, Jay B Thomas, William O Nachlas, Paul G Fitzgerald (2019). "First Discovery of Coesite in the Appalachians: Characterization of Prograde Metamorphism in a Taconic Metapelite". AGU Fall Meeting. 2019: V51B–03. Bibcode:2019AGUFM.V51B..03G
^ Levien L.; Prewitt C.T. (1981). "High-pressure crystal structure and compressibility of coesite" (PDF). American Mineralogist. 66: 324–333. Archived from the original (PDF) on 2016-06-04. Retrieved 2009-12-15

[”Anthony”-1] Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C. (eds.). "Coesite" (PDF). Handbook of Mineralogy. Vol. II (Silica, Silicates). Chantilly, VA, US: Mineralogical Society of America. ISBN 0962209716. Retrieved December 5, 2011

[”Chao”-2] Chao, E. C. T.; Shoemaker, E. M.; Madsen, B. M. (1960). "First Natural Occurrence of Coesite". Science. 132 (3421): 220–2. Bibcode:1960Sci...132..220C. doi:10.1126/science.132.3421.220. PMID 17748937. S2CID 45197811

[”Smyth”-3] Smyth, Joseph R.; Hatton, C.J. (1977). "A coesite-sanidine grospydite from the Roberts Victor kimberlite". Earth and Planetary Science Letters. 34 (2): 284. Bibcode:1977E&PSL..34..284S. doi:10.1016/0012-821X(77)90012-7

[Chopin-4] 4.0 ^4.1 Chopin, Christian (1984). "Coesite and pure pyrope in high-grade blueschists of the Western Alps: a first record and some consequences". Contributions to Mineralogy and Petrology. 86 (2): 107–118. Bibcode:1984CoMP...86..107C. doi:10.1007/BF00381838. S2CID 128818052

[Massonne”-5] Massonne, H.-J. (2001). "First find of coesite in the ultrahigh-pressure metamorphic area of the central Erzgebirge, Germany". European Journal of Mineralogy. 13 (3): 565–570. Bibcode:2001EJMin..13..565M. doi:10.1127/0935-1221/2001/0013-0565

[”Ghiribelli”-6] Ghiribelli, B.; Frezzotti, M.L. & Palmeri, R. (2002). "Coesite in eclogites of the Lanterman Range (Antarctica): Evidence from textural and Raman studies". European Journal of Mineralogy. 14 (2): 355–360. Bibcode:2002EJMin..14..355G. doi:10.1127/0935-1221/2002/0014-0355

[”Korsakov”-7] Korsakov, A.V.; Shatskiy, V. S. & Sobolev N.V. (1998). "Первая находка коэсита в эклогитах Кокчетавского массива (First occurrence of coesite in eclogites from the Kokchetav Massif)". Doklady Earth Sciences. 359: 77–81

[”Smith”-8] Smith, D.C. (1984). "Coesite in clinopyroxene in the Caledonides and its implications for geodynamics". Nature. 310 (5979): 641–644. Bibcode:1984Natur.310..641S. doi:10.1038/310641a0. S2CID 4330257

[”Schertl,”-9] Schertl, H.-P.; Okay, A.I. (1994). "A coesite inclusion in dolomite in Dabie Shan, China: petrological and rheological significance". Eur. J. Mineral. 6 (6): 995–1000. Bibcode:1994EJMin...6..995S. doi:10.1127/ejm/6/6/0995

[”O'Brien”-10] O'Brien, P.J., N. Zotov, R. Law, M.A. Khan and M.Q. Jan (2001). "Coesite in Himalayan eclogite and implications for models of India-Asia collision". Geology. 29 (5): 435–438. Bibcode:2001Geo....29..435O. doi:10.1130/0091-7613(2001)029<0435:CIHEAI>2.0.CO;2

[”Gonzalez”-11] Joseph Gonzalez, Suzanne Baldwin, Jay B Thomas, William O Nachlas, Paul G Fitzgerald (2019). "First Discovery of Coesite in the Appalachians: Characterization of Prograde Metamorphism in a Taconic Metapelite". AGU Fall Meeting. 2019: V51B–03. Bibcode:2019AGUFM.V51B..03G

[”Levien”-12] Levien L.; Prewitt C.T. (1981). "High-pressure crystal structure and compressibility of coesite" (PDF). American Mineralogist. 66: 324–333. Archived from the original (PDF) on 2016-06-04. Retrieved 2009-12-15

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