is the picture taken with a flash? There are crystals out there like alexandrite and I believe it was indicolite ( going by memory can be hard at times), but when alexandrite is exposed to artificial light it changes from purple to red, A ruby when exposed to uv light will flouresce inthe most amazing red color.
there are some that will change color as viewing aspect is changed.When we look for calcedony roses in the desert we use uv light to show us where the are kinda dangerous as scorpions also glow in uv light. but back to you question, there are crystals the change color, glow, its just another wonderful aspect of mother nature.
Blessings and peace: