Jade

The English name 'jade' derives from Spanish piedra de ijada ('flank stone'), recorded in 1565 and reflecting a folk belief in the stone's efficacy for ailments of the loins and kidneys. The Latin lapis nephriticus gave rise to the term 'nephrite'. Archaeologically, nephrite sources were exploited in Neolithic China (e.g., Liangzhu culture) and in regions feeding rivers of Xinjiang (Yurungkash and Karakash). Jadeite of the bright emerald-green varieties entered Chinese markets in quantity after about 1800, imported from Burma; over centuries jade objects became deeply embedded in ritual, funerary, and courtly systems, including use as grave furnishings (jade burial suits) and as imperial tribute.

Jade, as used in art and jewelry, denotes two mineralogical aggregates. Nephrite is an amphibole-group silicate of calcium and magnesium; it is typically green but can also be yellow, white (notably 'mutton fat' white), or black. Jadeite is a pyroxene-group silicate of sodium and aluminum with a broader color range: white through various greens (including the prized 'imperial' emerald-green), lavender, yellow, orange, brown, black, and rare blues. Both occur as tough, compact rocks worked into ornaments and ritual objects; the visual and tactile qualities (color, translucency, texture) determine cultural preferences.

Sources do not describe supernatural powers. Historical and folk attributions treat jade as possessing beneficial or protective qualities: the Spanish-derived name implies a reputation for treating flank and kidney ailments; in Chinese cultural history jade has been accorded symbolic and ritual efficacy, used in burial suits and cult objects to signify status and possibly to provide protective or continuity functions in funerary contexts. Such properties are cultural beliefs about material efficacy rather than documented agency.