Jade is not one stone but two quite different minerals
Call something jade and you might mean either of two unrelated rocks. Nephrite is built from calcium and magnesium; jadeite from sodium and aluminium. Both are tough, carvable and often green, and for thousands of years cultures from China to Mesoamerica to New Zealand treasured them above gold.
The English name comes from a Spanish phrase first recorded in 1565, piedra de ijada, or flank stone, because it was thought to cure ailments of the loins and kidneys. Nephrite derives from a Latin translation of the same phrase. In China a single character, yù, covers both stones, and it has grown into a general word for anything precious, appearing in expressions like jade countenance for a beautiful face. The common labels hard jade and soft jade stem from a mistranslation and are best avoided.
China's jade history is especially deep. Neolithic cultures such as the Hongshan and Liangzhu worked nephrite for tools and ceremonies, and one jade-like stone was mined as early as 6000 BC. Called the imperial gem, jade filled palaces and even went into burial suits for high-ranking nobles. Jadeite arrived in large quantities from Burma only after about 1800; its vivid green variety was nicknamed kingfisher jade, and it won favour with Qing aristocrats even as scholars stayed loyal to white nephrite. In 2010, the finest mutton-fat jade could fetch $3,000 an ounce, ten times the price of a decade earlier.
Elsewhere in Asia, Japan has used jade for about 7,000 years, back to the early Jomon period, and chemical analysis shows it all came from Itoigawa; only green stones were valued, perhaps as symbols of fertility. Comma-shaped jades hung from the gold crowns of Silla royalty in Korea. In prehistoric Southeast Asia, nephrite mined in eastern Taiwan and worked largely in the Philippines fuelled a wide trading network.
In New Zealand, Māori call nephrite pounamu, and the South Island is named Te Wai Pounamu after it. It is considered a taonga, a treasure, protected under the Treaty of Waitangi. Pieces gain mana, or prestige, as they pass down generations, and heirlooms with long known histories were given to seal important agreements. Adzes, short clubs and hei-tiki neck pendants were all carved from it. Across the Pacific, the Olmecs and Maya also prized jade for ritual.
Source: Jade
