Chrysoberyl Gemstones

Green Chrysoberyl

Why does alexandrite turn red?

Alexandrite, a variety of chrysoberyl, is an oddity to me. In sunlight, it’s green, but under incandescent light, it turns red. Does anyone know why? (and please, no “because it wants to” answers.)

I think I can answer this in more simpler terms. There’s flourescent light (white light) and incandescent light (yellow [...]