Heat Treating Blue Sapphire of Pailin, Cambodia

A total of 54 rough blue sapphire samples from Pailin gem field of Cambodia were studied. The samples can be classified into three groups on the basis of their colors and distinct appearance. They consist of trapiche-like blue sapphire, light blue and blue to dark blue groups. The main aim of this s...

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Main Authors: Kanyarat Kwansirikul, Panjawan Thanasuthipitak, Siwakon Chimnakphant, Opor Saidum
Format: บทความวารสาร
Language:English
Published: Science Faculty of Chiang Mai University 2019
Online Access:http://it.science.cmu.ac.th/ejournal/dl.php?journal_id=8775
http://cmuir.cmu.ac.th/jspui/handle/6653943832/64057
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Institution: Chiang Mai University
Language: English
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spelling th-cmuir.6653943832-640572019-05-07T09:59:45Z Heat Treating Blue Sapphire of Pailin, Cambodia Kanyarat Kwansirikul Panjawan Thanasuthipitak Siwakon Chimnakphant Opor Saidum A total of 54 rough blue sapphire samples from Pailin gem field of Cambodia were studied. The samples can be classified into three groups on the basis of their colors and distinct appearance. They consist of trapiche-like blue sapphire, light blue and blue to dark blue groups. The main aim of this study is to study heat treatment process of blue sapphire samples from Pailin gem field of Cambodia. Gemological properties and chemical compositions of these samples are also investigated. For heat treating experiments, the samples were divided into two batches according to the purpose of the heat treatments. Forty-five samples were heated in oxidizing condition to lighten dark blue color of the samples while nine samples were heated in reducing condition to intensify or develop the blue color. The results show that heating at 1200°C can lighten dark blue color and heating over 1400°C can develop or intensify blue color. The UV-Vis-NIR absorption spectra of all samples exhibit Fe3+ absorption peaks, Fe2+/Ti4+ IVCT and Fe2+/Fe3+ IVCT absorption bands. The more intense blue color intensified after heating, the stronger the intensity of Fe2+/Ti4+ IVCT absorption band. The Fe2+/Fe3+ IVCT absorption band probably contributes to the darker tone in the samples. Chemical compositions reveal iron (Fe) and titanium (Ti) are the most significant minor and trace elements because both of them are necessary for the color-causing mechanism in blue sapphire. 2019-05-07T09:59:45Z 2019-05-07T09:59:45Z 2018 บทความวารสาร 0125-2526 http://it.science.cmu.ac.th/ejournal/dl.php?journal_id=8775 http://cmuir.cmu.ac.th/jspui/handle/6653943832/64057 Eng Science Faculty of Chiang Mai University
institution Chiang Mai University
building Chiang Mai University Library
country Thailand
collection CMU Intellectual Repository
language English
description A total of 54 rough blue sapphire samples from Pailin gem field of Cambodia were studied. The samples can be classified into three groups on the basis of their colors and distinct appearance. They consist of trapiche-like blue sapphire, light blue and blue to dark blue groups. The main aim of this study is to study heat treatment process of blue sapphire samples from Pailin gem field of Cambodia. Gemological properties and chemical compositions of these samples are also investigated. For heat treating experiments, the samples were divided into two batches according to the purpose of the heat treatments. Forty-five samples were heated in oxidizing condition to lighten dark blue color of the samples while nine samples were heated in reducing condition to intensify or develop the blue color. The results show that heating at 1200°C can lighten dark blue color and heating over 1400°C can develop or intensify blue color. The UV-Vis-NIR absorption spectra of all samples exhibit Fe3+ absorption peaks, Fe2+/Ti4+ IVCT and Fe2+/Fe3+ IVCT absorption bands. The more intense blue color intensified after heating, the stronger the intensity of Fe2+/Ti4+ IVCT absorption band. The Fe2+/Fe3+ IVCT absorption band probably contributes to the darker tone in the samples. Chemical compositions reveal iron (Fe) and titanium (Ti) are the most significant minor and trace elements because both of them are necessary for the color-causing mechanism in blue sapphire.
format บทความวารสาร
author Kanyarat Kwansirikul
Panjawan Thanasuthipitak
Siwakon Chimnakphant
Opor Saidum
spellingShingle Kanyarat Kwansirikul
Panjawan Thanasuthipitak
Siwakon Chimnakphant
Opor Saidum
Heat Treating Blue Sapphire of Pailin, Cambodia
author_facet Kanyarat Kwansirikul
Panjawan Thanasuthipitak
Siwakon Chimnakphant
Opor Saidum
author_sort Kanyarat Kwansirikul
title Heat Treating Blue Sapphire of Pailin, Cambodia
title_short Heat Treating Blue Sapphire of Pailin, Cambodia
title_full Heat Treating Blue Sapphire of Pailin, Cambodia
title_fullStr Heat Treating Blue Sapphire of Pailin, Cambodia
title_full_unstemmed Heat Treating Blue Sapphire of Pailin, Cambodia
title_sort heat treating blue sapphire of pailin, cambodia
publisher Science Faculty of Chiang Mai University
publishDate 2019
url http://it.science.cmu.ac.th/ejournal/dl.php?journal_id=8775
http://cmuir.cmu.ac.th/jspui/handle/6653943832/64057
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