Nephrite and Jadeite are the only two true Jade stones. Even though they are both very similar in appearance they are two very distinct stones with different composition and structure. Nephrite is the older of the two and dates back to ancient civilizations. Nephrite is also the most common form of Jade and can be detected by its low luster and low translucency. It is also typically the more affordable of these two Jade stones. Nephrite consists of magnesium and calcium and is typically found in shades of mid to dark green and white although there are other varying colors available. Ancient and traditional Chinese Jade is made from Nephrite.
Jadeite was introduced from Burma in the late 1800's and has become the more sought after of the two as it is much rarer, more valuable and is considered a precious gemstone. Jadeite is a silicate mineral with sodium and aluminum and also contains traces of chromium and pyroxene. Jadeite can be found in a wide variety of colors which includes green, lavender, pink, black, yellow, and white. The rarest type of Jadeite is called Imperial Jade and is the most valuable. Imperial Jade contains traces of chromium which gives it its rich emerald green color.
Nephrite deposits can be found in locations such as China, New Zealand, Russia, Guatemala, Canada and the US. Jadeite deposits are found in Burma and can also be found in other countries like Russia, Japan, Canada and the US. Jade is typically mined in large quantities with large blocks sold as is to buyers in Asia. Buyers bidding on a stone do not usually have the opportunity to see the quality of the Jade until after the sale. There is usually a risk involved as to whether or not the buyer is getting a high quality stone.