Methods of altering the color of a diamond by irradiation and high-pressure/high-temperature processing

摘要

Embodiments of methods of altering the color of diamonds are disclosed. In an embodiment, a method for altering the color of diamonds includes identifying and selecting a diamond having a suitable nitrogen content, HPHT processing the selected diamond under diamond-stable conditions to alter the color of the selected diamond from a first color to a second color, irradiating the HPHT-processed diamond with an electron source having an energy between about 1 MeV and about 20 MeV so as to alter the color of the selected diamond from the second color to a third color, and annealing the irradiated diamond either under partial vacuum conditions, or under HPHT diamond-stable conditions so as to alter the color from the third color to a fourth color (e.g., pink, red, or purple, depending on the nitrogen content of the selected diamond).