black opal exhibits many different colors contrasted by a dark body tone. Frederick: It's simply the most stunning gemstone on the planet. It's just remarkably beautiful. You can put the thing ...

One might associate such colorful hard-stones with ladies’ watches, which have historically featured softer colors or ...

but when packed together in certain configurations can give rise to flashes of color. This is due to Bragg diffraction off the different layers in the opal, with different reflected photons ...