Orient is a combination of luster plus iridescence. This beautiful visual phenomenon is unique to pearls; no other gemstone in the world displays orient … they may display iridescent effects, but not orient. Additionally, not all pearls display orient – it is a rare visual effect that belongs only to the highest quality pearls.
Orient is different from the primary body color and secondary overtone colors pearls possess. For example, a pearl can have a white body color, a pink Rose overtone, and rainbow orient shifting and shimmering on top of that. This rainbow iridescence appears to float over the surface of the pearl.
So how is Orient created?
As explained earlier, pearls are layered with hexagonal semi-transparent aragonite platelets and conchiolin “glue” … But many of these layers are incomplete. They are uneven and overlap each other in layer upon layer.
Pearl surfaces viewed under microscopes reveal landscapes that appear almost scaly – in fact, this is a major reason why the Tooth Test works so well in determining whether a pearl is genuine or synthetic! That rasp you feel when scraping your teeth upon a pearl’s surface IS all these varying layers of crystal.
This “scaliness” is part of every single microns-thin layer of nacre all the way down to the pearl’s nucleus.
This delicate tracery of crystal can be thought of as the pearl’s individual fingerprint … no two pearls can ever be exactly the same.
Take a look at the slideshow below to get an idea of what I mean.