Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 20 May 1966:
Vol. 152. no. 3725, pp. 1061 - 1062
DOI: 10.1126/science.152.3725.1061
Prev | Table of Contents | Next

Articles

Color Center in Amethyst Quartz

Gerhard Lehmann 1 and Walter J. Moore 1

1 Chemical Laboratory, Indiana University, Bloomington

Treatment with x-rays increased the intensity of color of natural amethyst up to fivefold, and an electron paramagnetic resonance spectrum was detected. The intensity of the spectrum was proportional to the intensity of the optical absorption near 545 mµ. The EPR spectrum of the color center corresponded to a positive hole trapped on a substitutional Fe3+ ion in the quartz structure. We ascribe the color to a charge-transfer transition, Fe4+ + O2— rarr Fe3+ + O1-.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Determination of the potential for extrinsic color development in natural colorless quartz.
E. H. Nunes, V. Melo, F. Lameiras, O. Liz, A. Pinheiro, G. Machado, and W. Vasconcelos (2009)
American Mineralogist 94, 935-941
   Abstract »    Full Text »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)