Quahog Pearl
A purple non-nacreous pearl from the North Atlantic hard clam. Rare, and found by accident in the food trade.
Quahog pearls come from the same clam served in chowder, and they are usually discovered by someone eating dinner.
They are porcelain rather than nacreous, ranging from white through lavender to a deep aubergine purple, sometimes with a faint flame.
They cannot be cultured, and rich even purple examples are the ones that matter.
Conch Pearl
A pink, non-nacreous pearl from the queen conch, prized for a flame-like surface pattern. Cannot be cultured commercially.
Melo Pearl
A rare orange non-nacreous pearl from the Melo melo sea snail of Southeast Asia. Flame-patterned, like a conch pearl.
Natural Pearl
A pearl that formed with no human involvement at all. Vanishingly rare, and effectively absent from the retail market.