Ivory

Ivory is a hard, white, opaque substance that is the bulk of the teeth and tusks of animals such as the elephant, hippopotamus, walrus, etc. Prior to the introduction of plastics, it was used for billiard balls, piano keys, buttons and ornamental items. The word "ivory" was traditionally applied to the tusks of elephants.

The chemical structure of the teeth and tusks of mammals is the same regardless of the species of origin, and the trade in certain teeth and tusks other than elephant is well established and widespread. Therefore, "ivory" can correctly be used to describe any mammalian teeth or tusks of commercial interest which is large enough to be carved or scrimshawed.