Abstract
Organizer: 中国珠宝玉石首饰行业协会;
Argyle pink diamonds are type Ia and exhibit color-changing effects when illuminated with blue or UV light with a threshold at 465nm.The level of color loss is dependent on the wavelength of illumination, increasing with shorter wavelengths while the intensity of light determines the rate of color change. Color restoration is achieved with light between 570nm and 465nm.Below 300nm the color is partially restored unless the diamond is illuminated with IR light. An energy level diagram is proposed which includes single N and brown color centres.