Pure Pearls Glossary
Orient
The faint shifting rainbow that plays across the surface of a fine pearl, distinct from its lustre or its colour.
Orient is an interference effect from the stacked nacre platelets, the same physics that makes a soap bubble show colour.
It only appears with thick, well-ordered nacre, so orient is effectively proof of a pearl worth having. Thin-nacre and imitation pearls show none.
Look for it by rolling the pearl slowly under a single light and watching for colours that travel across the surface rather than sitting still on it.
When you are buying
Orient is the connoisseur's check, and it is the reason baroque and coin pearls can look more expensive than they are. Their broad, uneven surfaces show orient especially well.
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Lustre
How sharply a pearl reflects light. The single most important quality factor, and the one you can judge without any training.
Nacre
The material a pearl is made of: microscopic aragonite platelets glued in layers by conchiolin. Thickness determines both lustre and lifespan.
Overtone
A translucent secondary colour lying over a pearl's main body colour — most often rose, silver or green.
Coin
A flat, round disc. Large surface area for the weight, so it makes bold pieces that stay light.
Not sure what you are being sold?
Paste any pearl description — another shop’s listing, a message from a jeweller, an old certificate — and we will break it down term by term.