Ivory

Ivory is a valuable hard whitish bonelike substance, obtained from the tusks and teeth of certain large animals, most famously the elephant, but also from the walrus, narwhal, sperm whale, hippopotamus, and the tusks of certain large pigs.

Ivory is carved into various statues, ornaments and jewelery. Historically it was used in the manufacture of piano keys (hence the expression, "tickling the ivories" meaning to play the piano), and billiard balls.

The trade and transportation of ivory today is strictly regulated, as its value has prompted widespread poaching of ivory-yielding species, most of which are legally protected.

• The ivory gull is a pure white seabird of the high Arctic, named for its color.

• The ivory-billed Woodpecker is a very large woodpecker of Cuba and the Southern United States, now believed to have been extinct for several decades.