Spondylus is Latin, for spines on its back, which says it all. The shells, which are covered with intimidating spines, come in an array of bright colors. Spiny oyster shells were carved and traded far and wide from as early as 10,000 years ago.
Spiny oyster shells are found in the Gulf of California and the Pacific coast and south in the warm waters of South America. It is very difficult to harvest and polish and is much sought after by collectors.