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http://dx.doi.org/10.4191/kcers.2012.49.3.221

Color Enhancement of the Type II and Type I aB Brown Diamonds into Colorless by HPHT Process  

Song, Jeong-Ho (Department of Materials Science and Engineering, University of Seoul)
Song, Oh-Sung (Department of Materials Science and Engineering, University of Seoul)
Publication Information
Journal of the Korean Ceramic Society / v.49, no.3, 2012 , pp. 221-225 More about this Journal
Abstract
It is possible to enhance the color of the natural diamond with a high pressure high temperature(HPHT) process. We employed a pyrophyllite tube cell and cubic press apparatus for HPHT treatment on the brown colored Type II (5.6 GPa/ $1700^{\circ}C$/ 52 min), and Type I aB(5.6 GPa/ $1650^{\circ}C$/ 30 min) diamond samples. We investigated the microstructure, Types, fluorescence, properties of the diamonds with an optical microscopy, FT-IR, photoluminescence(PL) spectroscopy, Diamond-View, and micro-Raman spectroscopy. Two tinted brown diamonds changed into colorless just after the HPHT process. Optical microscopy showed that no crack and significant inclusion evolution occurred during the HPHT process except the small graphite spot appeared in Type I aB sample. FTIR spectrum confirmed that no Type, amber center, and platelet defect change with the HPHT treatment. Diamond-View could not distinguish the HPHT treated diamonds from the naturals. PL spectroscopy showed that N3 and H3 color centers remained even after HPHT process. Consequently, we successfully changed the color of diamonds into colorless by 5.6 GPa HPHT process.
Keywords
HPHT; Tinted brown diamond; Colorless diamond; Type II; Type I aB;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
Times Cited By SCOPUS : 1
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