Assertion: emerald's color | /r/CreatedBy | a color center
Facets:
value: by pseudochromatic light interference
type: CAUSE
Source sentences:
text: To give only one example: deep blue colors may be produced by idiochromatic copper (shattuckite), allochromatic cobalt (blue spinel), by a color center (Maxixe-type irradiated beryl), by charge transfer between iron and titanium (blue sapphire), by molecular orbital effects in S-3 units (lapis lazuli), by boron acceptors in a band gap (blue diamond), and by pseudochromatic light interference (blue regions in opal).