 |
 |
Sorry, may letter was unfinished! Bernardo, The kinetic ordering and growth dissymmetrisation is a prevalent mechanism for birefrigent garnets. Some publications on theis subjects are: Akizuki M. Origin of optical variations in grossular-andradite garnet. American Mineralogist, Volume 69, 1984, pages 328-338. Akizuki M. Growth structure and crystal symmetry of grossular garnets from the Jeffrey mine, Asbestos, Quebec, Canada. American Mineralogist, Volume 74, 1989, pages 859-864. Hariya Y., Kimura M. Optical anomaly garnet and its stability field at high pressures and temperatures. J. Fac. Sci. Hokkaido Univ., Ser. IV., vol. 18, No. 4, 1978, pp. 611-624. Hirai H., Nakazawa H. Grandite garnet from Nevada: confirmation of origin of iridescence by electron microscopy and interpretation of a moire-like texture. American Mineralogist, Volume 71, 1986, pages 123-126. Hirai H., Nakazawa H. Visualizing low symmetry of a grandite garnet on precession photographs. American Mineralogist, Volume 71, 1986, pages 1210-1213. Shtukenberg A.G., Popov D.Yu., Punin Yu.O. Growth ordering and anomalous birefringence in ugrandite garnets. Mineralogical Magazine, Vol. 69 (4), 2005, pp. 537-550. Hofmeister A.M., Schaal R.B., Campbell K.R., Berry S.L., Fagan T.J. Prevalence and origin of birefringence in 48 garnets from the pyrope-almandine-grossularite-spessartine quaternary. American Mineralogist, Volume 83, 1998, pages 1293–1301. and Shtukenberg A., Punin Y.O. Optically Anomalous Crystals. / Ed. by Bart Kahr. Springer, 2007. http://link.springer.com/book/10.1007/1-4020-5353-3 Best wishes, Pavel Azimov, Ph.D. <[log in to unmask]> The Institute of Precambrian Geology and Geochronology RAS, St.Petersburg, Russia >Пятница, 16 декабря 2016, 20:33 +03:00 от Bernardo Cesare <[log in to unmask]>: > >Dear all, >we have found a highly deformed blueschist showing optically >anisotropic garnet, not yet probed but presumably a Fe-Mg(-Mn) solution. >A first, quick search for similar occurrences didn't bring results so >I'd greatly appreciate your feedback, and to receive references of >studies that might help us in the interpretation of this behaviour. > >Thank you very much in advance! >Regards, >Bernardo > >-- >******************************************************************* >Bernardo Cesare >Dipartimento di Geoscienze, Universita' di Padova >Via G. Gradenigo, 6, I-35131 PADOVA ITALY >Tel: + +39-049-8279148 Fax: + +39-049-8279134 >email: [log in to unmask] >Web site: http://147.162.183.153/bernardo/berning.html >ACME Group: http://147.162.183.153/ACME >MicROCKScopica: http://www.microckscopica.org >InsiemePerWamba: http://www.insiemeperwamba.org >******************************************************************* > >"The only real failure is the failure to try, and the measure of >success is how we cope with disappointment, as we always must." > > From the >movie: The Best Exotic Marigold Hotel