Jade is a translucent to opaque stone, which varies in color from pale to rich in color. Originally prized for its toughness and used in tools and weapons by prehistoric man, jade has a varied history. This gem has been known as the "royal gem" in China for 5000 years, and it was once valued more than gold by the Mayans and Aztecs. The name "jade" is derived from the Spanish "piedra de ijada" or loin-stone where it was thought to have medicinal powers to heal kidney ailments.
Jade is divided in two groups: Jadeite and Nephrite. Nephrite is the more common of the two and may range in color from dark green to grey-green. In some instances it can also be white, reddish or yellowish. Jadeite, which is rarer, is usually green but also includes white, pink, red, violet, black and brown hues. It's normal for jade to contain streaks and other blemishes. These are not necessarily considered flaws. In fact, some of the patterns created are considered to add value to a piece.
||Various shades of green (nephrite) or every color of the rainbow (jadeite)
||Jadeite has a Mohs' hardness rating of 7. Nephrite has a Mohs' hardness rating of 6.5.