The individual silica nanoparticles (glass beads, basically ... This is due to Bragg diffraction off the different layers in the opal, with different reflected photons interferring with each ...

Set with 137 beads of Mexican fire opal that are affixed to the case by tiny 18-karat gold pins, the 36.5-millimeter yellow gold watch boasts a matte glass-blasted finish and is complemented by an ...