Mother of pearl buttons and shell buttons are both types of "natural" buttons, meaning that they are made from substances found in nature, rather than being manufactured, like plastic or metal buttons.

The inner lining of the shells of mollusks such as oysters and mussels has an opalescent quality, due to the presence of a substance called nacre. In oysters, nacre is the raw material from which pearls are formed. This gives the inner lining of mollusk shells a beautiful, pearly quality, leading people to call it "mother of pearl." Mother of pearl buttons are made from this lining.

Buttons can be made from many kinds of shells, so it is difficult to assign any specific characteristics to them. Shell buttons can be carved from almost any layer of the shell, and so they vary widely in color, shape and size.

Mother of pearl buttons come in a variety of sizes, with the larger buttons being highly prized as they are more fragile and difficult to obtain. Shell buttons may be made from a variety of freshwater and marine sea life, from abalones to scallops.

Shell buttons have been used in many cultures throughout history, as they are relatively easy for pre-industrial cultures to produce. Mother of pearl buttons became extremely popular during the early 19th century, and remained so through the Victorian era.

Although both shell buttons and mother of pearl buttons can be very beautiful, they are also more delicate and brittle than manufactured buttons. Despite their perishable qualities, mother of pearl and shell buttons are still highly sought after, due to their decorative beauty.