Jadeite and Nephrite Gemstones

Two gemstones bear the name jade, jadeite and nephrite gemstones. Nephrite, first known as yu, was treasured by the Chinese for centuries. Its current name, and the word "jade," both came from the Europeans via the Spanish conquistadores who invaded South America

. Like the Chinese, the South Americans, especially the Aztecs, valued a particular green stone above all else, even gold. Also like the Chinese, they attributed healing powers to that stone. They often used their green gem to relieve urinary ailments. Because of this, the Spanish referred to it as the "stone of the loins" or sometimes, "stone of the kidneys." Nephrite is derived from the Latin word for kidney, and jade is a corruption of the French word for loins.

All opaque green stones were known as nephrite or jade until the development of crystallography. At that time, mineralogists began classifying gemstones according to what minerals they were made from and how those minerals formed solid substances. In that process, they discovered that, despite the outward similarity, two completely different minerals were named jade. They renamed the second stone jadeite.

Although they both include silica, magnesium is the secondary mineral in nephrite while jadeite contains aluminum. Pure jade of either kind is white. Trace amounts of iron provide the green in nephrite; and jadeite, like emeralds, gets its green from chromium.

Other chemical impurities yield other colors: nephrite may be beige, yellow, blue or black, among others. White, blue-green, lavender, orange and red are the primary jadeite colors. Jadeite colors are usually more vivid than nephrite shades, especially the greens. Because of this, jadeite is more highly valued than nephrite.

Mineralogists and jewelers take care to distinguish between nephrite and jadeite. The general public continues to refer to either as jade.

Although they first used nephrite, the Chinese now prefer jadeite because of its color. It's been named Imperial Jade.

Other names, such as New Jade, Korean Jade, Stygian Jade, Pagoda stone, Mexican Jade and Indian Jade all refer to imitations. None of these are authentic jade. Poor quality jade may also be dyed.

People, especially the Chinese and the Aztecs, utilized jade in many ways through the centuries. It has functioned as money, played an important role in ceremonies, been made into art and jewelry and applied to the body or powdered and drunk as medicine. Those who attribute powers to crystals believe that jade brings love, healing, longevity, wisdom and prosperity.

Although some historians believe that the jade first used in China was imported, jade is currently mined there. It's also mined in  Myanmar (Burma), New Zealand, Siberia, South America and the United States.