JADE can be nephrite, jadeite or chloromelanite. All other names, such as New Jade (Bowenite), India jade (Aventurine), Honan jade (Serpentine) and many others do NOT apply to genuine jade.

 

Nephrite jade is the historical Chinese Jade, or Stone from Heaven, a stone revered by the Chinese for more than 7000 years. It is still found in Turkistan. Nephrite is prized for its special qualities: its extreme toughness, (the toughest of any natural stone), and a smooth polished feel,  especially the older pieces!.

Colors of Nephrite Jade range from pure white to all shades of green, plus other colors, such as brown, yellow etc.

Jadeite was introduced to China from Burma  about 300 years ago. Gem quality Jadeite is extremely rare and can be extremely expensive.  The so-called Chinese Jade (Jadeite) was never found in China. It should be called "Chinese Carved Jade".

Colors of jadeite range from white to black with intense greens and lavender being the most sought after.

Chloromelanite ( related to Jadeite) is the stone which ancient man used world-wide mainly to make stone tools,  since many thousands of years ago. It is mainly black (oiled, otherwise grey) , but one can easily see with a loupe some green in it.

Maw Sit Sit is known by the Chinese as "Old Emerald Jade".  Maw sit sit has a similar hardness to Jadeite and even blends with Jadeite - two minerals pressed, over time, to become one.

 

MORE INFORMATION AVAILABLE AT http://mineral.galleries.com/minerals/gemstone/jade/jade.htm