Jade

Jade is an ornamental green rock. The term jade is applied to two different metamorphic rocks that are composed of different silicate minerals: 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. Jadeite is a sodium- and aluminium-rich pyroxene. The precious form of jadeite jade is a microcrystalline interlocking growth of jadeite crystals. 2Etymology The English word jade is derived (via French l'ejade and Latin ilia "flanks, kidney area") from the Spanish term piedra de ijada (first recorded in 1565) or "loin stone", from its reputed efficacy in curing ailments of the loins and kidneys. Nephrite is derived from lapis nephriticus, a Latin translation of the Spanish piedra de ijada. 2Overview 3Nephrite and jadeite Nephrite and jadeite were used from prehistoric periods for hardstone carving. Jadeite has about the same hardness as quart