The "Six Ritual Jades"- http://en.wikipedia.org/wiki/Chinese_jade
bi- a flat disk with a hole in its center. Represents the heavens. Reserved for barons.
Hu- flat and circular. Represents west
Cong- a ring cuff shape. Represents earth.
huang- a flat, half-ring pendant. Represents the north. Reserved for dukes
gui- flat and blade like. Represents the east. Reserved for earls.
zhang- Flat and blade like. Represents south. Reserved for the king.
Jade Jewelry- http://www.jadefinejewelry.com/
1. Jade is delicate- avoid bumping it. Although sometimes a crack cannot be seen by the naked eye, the interior structure may have been damaged. As time goes on, it will appear and reduce the value of the piece.
2. Jade is porous so its important not to let it become greasy.
3. When not in use store in a box away from sunlight.
4. Avoid perfume, perspiration or chemicals. The brightness of jade risks corrosion, especially emerald and other high quality jade.
5. Avoid long periods of sunlight for a long time, or it may expand and the quality will change slightly.
6. Jade has certain water content so keep it in an area of humidity to protect it from over-drying.
Folk lore and Jade Legends-