Pronunciation

al-ig-ZAN-drite

Alexandrite effect — also called color change — is the appearance of distinctly different colors in the same gemstone when viewed under different illuminants, typically daylight versus incandescent or candlelight. Named after the gemstone alexandrite (chrysoberyl), the effect is caused by selective wavelength absorption from trace chromophores (chromium, iron, vanadium) producing a transmission spectrum that varies with the illuminant’s color temperature.