The Dynamic Earth @ National Museum of Natural History

Main Menu > Plate Tectonics and Volcanoes > The Himalaya > Jade

[Photo: World Distribution of Jade Deposits]

Jade, the "gemstone" mined from subduction zones, is really two types of metamorphic rock: nephrite and the rarer jadeitite. Jadeitite is rare because it forms only along faults deep within active subduction zones.

The Colors of Jade

The internal arrangement of jade crystals makes jade tough, allowing it to be carved into delicate shapes like the vase (at right). Traces of chromium impart the brilliant green. Manganese produces the mauve and lilac shades. The white parts are impurity-free.

Inside Jade

Here's the inside story on the two kinds of jade. Jadeitite is a puzzle-block arrangement of pyroxene crystals (left photo). Nephrite is a fine-grained mass of fibrous amphibole crystals (right photo).