Jade

Jade is an ornamental stone. The term jade is applied to two different metamorphic rocks that are made up of different silicate minerals: the 1st type, Nephrite consists of a microcrystalline interlocking fibrous matrix of the calcium, magnesium-iron rich amphibole mineral series tremolite (calcium-magnesium)-ferroactinolite (calcium-magnesium-iron). The middle member of this series with an intermediate composition is called actinolite (the silky fibrous mineral form is one form of  asbestos). The higher the iron content the greener the colour. The 2nd type is Jadeite, a sodium - and aluminium - rich pyroxene. The gem form of the mineral is a microcrystalline interlocking crystal matrix.