Conch pearls differ from traditional, nacreous pearls in both structure and classification. They are calcareous concretions and do not meet the classic definition of a pearl as a layered, nacreous object, but are still true pearls as they originate organically from a mollusk.

They don’t diffract light or exhibit orient. Instead, conch pearls display a porcelain-like surface, and in fine examples, a flame-like pattern that appears to move just beneath the surface.

Color, shape and size can vary widely. The most prized are red and dark pink, but other colors such as cream, white, yellow, orange and brown tones are also seen. Fine examples exhibit symmetry, strong coloration, and well-defined flame structure.