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公开(公告)号:US20040146451A1
公开(公告)日:2004-07-29
申请号:US10737541
申请日:2003-12-15
发明人: Suresh Shankarappa Vagarali , Steven William Webb , William Edwin Jackson , William Frank Banholzer , Thomas Richard Anthony , George Rene Kaplan
IPC分类号: C01B031/06
CPC分类号: B01J3/06 , B01J3/062 , B01J2203/062 , B01J2203/0655 , B01J2203/0695 , C30B29/04 , C30B33/00
摘要: The present invention is directed to a method for changing the color of colored natural diamonds. The method includes placing a discolored natural diamond in a pressure-transmitting medium which is consolidated into a pill. Next, the pill is placed into a high pressure/high temperature (HP/HT) press at elevated pressure and elevated temperature for a time sufficient to improve the color of the diamond. The diamond may be exposed at elevated-pressure and elevated-temperature conditions within the graphite-stable region of the carbon-phase diagramnullwithout significant graphitization of the diamond, or above the diamond-graphite equilibrium and within the diamond-stable region of the carbon-phase diagram. Finally, the diamond is recovered from said press. Colorless Type Ia and Type II diamonds may be made by this method.