Changes of optical defects by HPHT-process with pre-irradiation in the HPHT synthetic yellow diamond

Abstract

The 0.066 ct Fancy Vivid Yellow HPHT synthetic diamond tested our Laboratory showed B centre and B2 centre (platelets) in addition to C and A centres in FTIR analysis. The nitrogen concentration reached to 700 ppm in total, and a C-H related peak was detected at 3107 cm^-1. We concluded This stone is a HPHT synthetic diamond produced using a Co solvent and then irradiated and HPHT treated after the growth, i.e., a HIH (HPHT growth/ Irradiation/ HPHT treatment) synthetic diamond.