Abalone is a single-shelled marine mollusk that has been highly prized for thousands of years, and for multiple reasons. This amazing creature has been, and still is, harvested as a food source. Its mild, sweet meat is considered a delicacy by gourmets around the world. The shell of abalone has a thick inner layer which is composed of nacre (mother of pearl), which is highly iridescent, which is used in jewelry designs.