Contra Luz opal. 2.9ct oval. Beautiful play of color

Have you heard about Contra Luz opal? 
It's a beautiful stone that appears either clear,  milky white, or sometimes a golden color like this one.  But they hold a surprise!
Contra Luz means "against the light" in Spanish.  Sometimes, these stones have a little color play even without light behind them,  but "against the light" they shimmer with greens,  blues oranges, and reds. 
Often, these stones are set with highly polished 24k gold as a parabolic reflector or just in an open setting where they can catch the light.  Sometimes, designers will use a small LED behind the setting and a tiny watch battery. 
No matter how you set them,  they will be absolutely amazing.
This stone weighs 2.9ct and measures 12x 10mm.