Coral fossil (agatized coral) preserves ancient reef colonies in stone: silica slowly replaced the coral skeletons, leaving flower-like polyp patterns in tan, gray and rose. Indonesia and Florida are famous sources; hardness about 7 once agatized — a paleontology lesson you can wear.Our fossil corals are natural, certified by GEMIC Institute and photographed piece by piece — each flower pattern is unrepeatable. Tracked worldwide delivery and 30-day returns on every order.