<abstract xmlns="http://www.w3.org/1999/xhtml"><p> Certain variety of Madagascar color sapphires (fancy sapphires) has orange-red color, which shades don’t let to consider them as the rubies. Heat treatment experiments in reducing atmosphere were carried out on such sapphires for the purpose of improving their color characteristics. Chromium (III), iron (II and III), titanium (IV) chromophore impurities in natural corundum and chromophore centers with their participitation are considered. A special attention is paid to spectral characteristics of chromophore centers. Behavior of the chromophore centers under heat treatment and their influence on the color of fancy sapphires are studied. Color modification mechanism was proposed on the basis of microprobe and spectral analyses data. The proposed enhancement technique allows to improve color characteristics of fancy sapphires.</p></abstract>

Certain variety of Madagascar color sapphires (fancy sapphires) has orange-red color, which shades don’t let to consider them as the rubies. Heat treatment experiments in reducing atmosphere were carried out on such sapphires for the purpose of improving their color characteristics. Chromium (III), iron (II and III), titanium (IV) chromophore impurities in natural corundum and chromophore centers with their participitation are considered. A special attention is paid to spectral characteristics of chromophore centers. Behavior of the chromophore centers under heat treatment and their influence on the color of fancy sapphires are studied. Color modification mechanism was proposed on the basis of microprobe and spectral analyses data. The proposed enhancement technique allows to improve color characteristics of fancy sapphires.

Heat treatment enhancement of natural orange-red sapphires

D. Mendeleyev University of Chemical Technology of Russia, Department of chemistry and technology of crystals, 125480, Geroev Panfilovtsev str. 20/1, Moscow, Russia

Advances in Materials Science

{"article-title":"Heat treatment enhancement of natural orange-red sapphires"}

Certain variety of Madagascar color sapphires (fancy sapphires) has orange-red color, which shades don’t let to consider them as the rubies. Heat treatment...

Heat treatment enhancement of natural orange-red sapphires

Published Online: Oct 22, 2012

Page range: 31 - 44

DOI: https://doi.org/10.2478/v10077-012-0006-3

Keywords
corundum, fancy sapphires, enhancement, heat treatment, chromophore center

This content is open access.

Heat treatment enhancement of natural orange-red sapphires

Published Online: Oct 22, 2012

Page range: 31 - 44

DOI: https://doi.org/10.2478/v10077-012-0006-3

Keywordscorundum, fancy sapphires, enhancement, heat treatment, chromophore center

This content is open access.

Keywords
corundum, fancy sapphires, enhancement, heat treatment, chromophore center