Ivory is the teeth of animals.
Chemically, ivory is similar to bone and antler, and comprises a collagen matrix with a mineral component. Unlike bone, ivory has no blood vessel system, and is therefore more dense. The most commonly found ivories in North America come from elephant, walrus, sperm whale, and hornbill. It is possible to tell these ivories apart, as they are structurally different. This category includes ivory from both Indian and African elephants, as well as ivory from mammoths and mastodon.