Spiny Oyster Shell
Living Spondylus shells are, indeed, very spiny, but the polished product looks very smooth, with some of its color variation. Divers collect Spiny Oyster by hand, making the work laborious and relatively expensive, with some risks.
In the American Oceans, the Spondylids occur along the North American coasts, as far north as North Carolina, on the Atlantic Coast, and northwestern Mexico, on the Pacific Coast. It develops in waters to South America. The Orange Spiny Oyster occurs in shallow to moderately deep waters, where snorkelers and scuba divers readily harvest them. Purple Spiny Oysters grow in deeper water, making them more difficult to find and harvest.