Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-28T06:23:42.220Z Has data issue: false hasContentIssue false
  • English
  • Français

Relationship between the crystallographic orientation and the ‘alexandrite effect’ in synthetic alexandrite

Published online by Cambridge University Press:  05 July 2018

Yan Liu ,
James E. Shigley ,
Emmanuel Fritsch  and
Scott Hemphill
Yan Liu
Affiliation:
GIA Research, Gemological Institute of America, 1660 Stewart Street, Santa Monica, Ca 90404-4088, USA
James E. Shigley
Affiliation:
GIA Research, Gemological Institute of America, 1660 Stewart Street, Santa Monica, Ca 90404-4088, USA
Emmanuel Fritsch
Affiliation:
GIA Research, Gemological Institute of America, 1660 Stewart Street, Santa Monica, Ca 90404-4088, USA
Scott Hemphill
Affiliation:
GIA Research, Gemological Institute of America, 1660 Stewart Street, Santa Monica, Ca 90404-4088, USA
Get access Rights & Permissions [Opens in a new window]

Abstract

The transmittance spectra of a synthetic alexandrite recorded along directions parallel to the three crystallographic axes are generally similar, but the observed colour changes along these directions under different light sources are quite different. Calculated hue-angle changes for the colours observed under different pairs of C.I.E. standard illuminants are the largest for light travelling parallel to the a-axis. Therefore, alexandrite should be cut as a gemstone with the top facet oriented parallel to (100) for it to show the most dramatic change in colour.

Keywords

chrysoberylalexandritealexandrite effectcolour
Type
Mineralogy
Information
Mineralogical Magazine , Volume 59 , Issue 394 , March 1995 , pp. 111 - 114
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1995

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bukin, G. V., Matrosov, V. N., Orekhova, V. P., Remigailo, Y. L., Sevastyanov, B. K., Syomin, E. G., Solntsev, V. P. and Tsvetkov, E. G. (1981) Growth of alexandrite crystals and investigation of their properties. J. Cryst. Growth, 52, 537–541.CrossRefGoogle Scholar
Commission Internationale de FEclairage (C.I.E.) (1986) Colorimetry, 2nd Edition. Publication No. 15. 2, Vienna.Google Scholar
Farrell, E. F. and Newnham, R. E. (1965) Crystal-field spectra of chrysoberyl, alexandrite, peridot, and sinhalite. Amer. Min., 50, 1972–81.Google Scholar
Goldschmidt, V. (1913) Atlas der Krystallformen. C. Winters Universitatsbuchhandlung, Heidelberg.Google Scholar
Hassan, F. and El-Rakhawy, A. (1974) Chromium III centers in synthetic alexandrite. Amer. Mineral. 59, 159–65.Google Scholar
Liu, Y., Shigley, J. E., Fritsch, E. and Hemphill, S. (1994) The ‘alexandrite’ effect in gemstones. Color Res. Appl., 19, 186–92.CrossRefGoogle Scholar
Schmetzer, K., Bank, H. and Gubelin, E. (1980) The alexandrite effect in minerals: chrysoberyl, garnet, corundum, fluorite. Neues Jahrb. Mineral., Abh., 138, 147–64.Google Scholar
White, W. B., Roy, R. and McKay-Crichton, J. (1967) The ‘alexandrite effect': an optical stud. Amer. Mineral., 52, 867–71.Google Scholar
Worth, F. I. and Perovsky, L. A. (1842) Uber Alexandrit und Chrysoberyll. Verhandlung Russ.-Kaiserl. Mineral. Ges. St. Petersburg, Vol. 1, No. 1, (not seen; cited in Sinkankas, J., Gemology — An Annotated Bibliography, Vol. 2, p. 1145, Scarecrow Press, Metuchen, New Jersey, 1993).Google Scholar