Originally, all jade objects were thought to be made from the same material. However, in 1863 a Frenchman, Alexis Damour, discovered that the material known as “jade” could be divided into two different minerals: jadeite and nephrite.

Because these two materials can be difficult to distinguish, and because the word “jade” is so entrenched in common language, the name “jade” is still widely used across many societies, industries, and academic disciplines.

In this article, the word “jade” will be used for undifferentiated materials. “Jadeite” or “nephrite” will be used when the identity of the material is known. The word “nephrite” is also an imprecise term. It is used for materials composed of the minerals actinolite and tremolite.

Jade Ax: A reproduction of a Mayan or Aztec ax head.