Ivory

Ivory is a hard yellowish-white material made from the tusks and teeth of animals such as elephants, hippopotamuses and walruses. Ivory is now very rare and expensive since there are restrictions on hunting elephants for ivory. There are also laws against the trade of ivory. Some countries (including Zimbabwe and South Africa) argue that these laws should be removed or changed, to allow them to sell some ivory. 

Ivory has been used to make piano keys, billiard balls, handles and small ornaments. After ivory was banned, these items were usually made from plastic. Many of the earliest plastics were meant to be substitutes for ivory. Ivory has been used in artworks, such as carvings, since ancient times. 

Category:Natural materials