Jade pieces in various colors. Photo © Joel E. Arem, PhD, FGA. Used with permission.

What is Jade?

Jade is a term used to describe two different silicate minerals — jadeite and nephrite.

Jadeite is a sodium-aluminum silicate rock with a polycrystalline structure. It belongs to a group of rock-forming minerals called pyroxene (which includes minerals such as diopside and spodumene).

how does jade form - jadeite stone
Jadeite stone. Photo source: Canva.

Nephrite belongs to the amphibole mineral supergroup, a fibrous variety of the tremoliteactinolite series.

how does jade form - nephrite stone
Nephrite stone. Photo source: Canva.

Both types of jade form through metamorphism, but the processes differ.

How Does Jadeite Jade Form?

Jadeite forms along active subduction zones in high-pressure, low-temperature environments deep in the Earth’s mantle, where basaltic ocean plates subduct (sink) under lighter continental plates. Jadeite occurs in metamorphic rocks. These rocks undergo further mineral transformation after forming in the Earth’s crust due to intense heat and pressure. In this case, the mineral transformation occurs in the presence of water and carbonates derived from ocean floor sediments.

Water-saturated sedimentary marine rocks form small cracks and break when dragged under continental plates. High temperature and pressure squeeze the water out of these rocks, creating