Jadeite

Jadeite is formed only in the subduction zones of continental margins, where rock undergoes metamorphism at high pressure but relatively low temperature. Jadeite is the principal mineral making up the most valuable form of jade, a precious stone particularly prized in China. Most gem-quality jadeite jade comes from northern Myanmar. Jade tools and implements have been found at Stone Age sites, showing that the mineral has been prized by humans since before the beginning of written history. The name jadeite is derived (via French: jade and Latin: ilia) from the Spanish phrase "piedra de ijada" which means "stone of the side". The Latin version of the name, lapis nephriticus, is the origin of the term nephrite, which is a different mineral that also shares the common name jade. Jadeite is a hard, extremely tough, rare mineral of the clinopyroxene family of minerals.