Definition of alexandrite effect
The property of some chrysoberyl and other minerals and stones to appear green in sunlight, but red under incandescent illumination.
References:
Yan Liu, James Shigley, Emmanuel Fritsch and Scott Hemphill (1994): The “alexandrite effect” in gemstones. Color Research & Application 19, 186–191.
https://en.wikipedia.org/wiki/Chrysoberyl#Alexandrite
https://www.gia.edu/alexandrite-quality-factor
References:
Yan Liu, James Shigley, Emmanuel Fritsch and Scott Hemphill (1994): The “alexandrite effect” in gemstones. Color Research & Application 19, 186–191.
https://en.wikipedia.org/wiki/Chrysoberyl#Alexandrite
https://www.gia.edu/alexandrite-quality-factor