Netsuke carved of mammoth ivory, depicting a monkey holding a skull.
The only copy, repeat isn't possible.
Vegetable ivory or tagua nut is a product made from the very hard white endosperm of the seeds of certain palm trees. Vegetable ivory is named for its resemblance to animal ivory. Species in the genus Phytelephas (literally "elephant plant"), native to South America, are the most important sources of vegetable ivory. The seeds of the Caroline ivory-nut palm from the Caroline Islands, natangura palm from Solomon Islands and Vanuatu, and the real fan palm, from Sub-Saharan Africa, are also used to produce vegetable ivory.
The material is called corozo or corosso when used in buttons.