What Is Cat's Eye?

Cat's Eye (operculum) is part of many shelled animals. It is the calcified, disc-shaped "trap-door" that opens and closes to protect the animal inside its shell.

The operculum from a species of sea snail called the Tapestry Turban, found in the tropical and sub-tropical Pacific is eye-like with a natural cabochon shape and is used in jewelry.

This jewelry was popular in Victorian era Britain. Throughout many centuries, visitors to the South Seas have brought home trinkets featuring this exotic gem.

Photo by Douglas Yaple