Abstract
In this chapter, characteristic transformations of impurity-defect structure of diamonds during HPHT treatment are discussed. Detailed consideration of the processes of nitrogen defect aggregation and dissociation is given. Stimulating action of vacancies and nickel in the nitrogen-defect transformation processes is discussed. It is shown that the understanding of the nitrogen defect transformation processes is a key to recognition of HPHT-treated diamonds. Color transformations of natural diamonds of different types during HPHT treatment are discussed in detail. Special attention is paid to discoloration of brown diamonds and achievement of red/pink colors. It is shown that the transformations of the nitrogen-related defects and vacancy aggregates are the major processes determining the color change in HPHT-treated diamonds. Typical defect transformations during commercial HPHT treatment are discussed.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
