How do seashells form?

Secretion of different kinds of proteins at different times and places in the seashells seems to direct the type of calcium carbonate crystal formed. Calcified bone or shell of turtles, on the other hand, does not readily form different crystals. read more

Seashells are the exoskeletons of mollusks such as snails, clams, oysters and many others. Such shells have three distinct layers and are composed mostly of calcium carbonate with only a small quantity of protein--no more than 2 percent. read more

The seashells you see on the beach were once home to a wide range of creatures like snails and clams. These creatures use salt and chemicals from sea water to form their hard outer shells, and discard the shells when they die. read more

A seashell or sea shell, also known simply as a shell, is a hard, protective outer layer created by an animal that lives in the sea. The shell is part of the body of the animal. Empty seashells are often found washed up on beaches by beachcombers. read more