Tuesday, December 02, 2008

Ivory

Ivory is a white to creamy colored organic substance or mineraloid. It has a hardness of 2-3 and low specific gravity of 1.7-2. The fracture is fibrous and it is opaque to translucent. Ivory can refer to the tusk or teeth of elephant, hippopotamus, narwhal, sea lion, and wild boar. There is a worldwide ban on trade in elephant ivory (since 1989) and US ban since 1994.