opalescent

/ˈoʊpəˌlɛsnt/

Other forms: opalescently

If you're familiar with the way that the gemstone opal shimmers like a pearl, then you'll understand that something opalescent reflects the light in the same way.

Opal is a beautiful mineral with an almost magical, layered reflective quality that catches the eye the way a pearl does. Something opalescent has that same reflective quality. High-quality guitars, for example, often have opalescent inlays in the fingerboard that are not only beautiful but also useful. They can help the guitar player find her way around the instrument. Don't be fooled by imitations! Many fake jewels have an opalescent quality that mimics real pearl, but it's plastic, all the same.

Definitions of opalescent

1. adjective

   having a play of lustrous rainbow colors
   “a milky opalescent (or opaline) luster”

   synonyms: iridescent, nacreous, opaline, pearlescent

   bright

   emitting or reflecting light readily or in large amounts