General information of jade
Overview of Xiu jade(Xiuyan Jade)
Distinguish quality jade from fake or inferior jade
Jade's grading system in common language

1) The weight of the piece. Jade, even the lesser density nephrite jade like Xiu jade, is heavier than regular glass or resin. For Burma jadeite, the weight is very easy to tell, since you can feel the heavy sensation in your palm when you are handling it.

2) Observe carefully, there are tiny air bubbles in fake jade most of the time..

3) Jade has the property of cooling very fast and remains in cool temperature. Hold a piece in your hand until you feel that the temperature of the piece is equal to your body's, then open your palm right away and put the jade aside. After about 25 seconds in regular room temperature surrounding, use the tip of tongue to feel the piece. If there is a very cool sensation, then it is most likely jade.

4) Jade is more durable than glass. If you wear a piece and it breaks very easily, it definitely is not jade. Even the soft nephrite jade should not break easily.

5) Texture, the texture of jade is very smooth. Run your finder nail on the surface of the piece, if it feels bumpy on your nail, but the surface appears to be smooth, it is most likely not jade. This method works better on glass and other synthetic resin fake jade.

6) The Sound test. Let two jade bracelets loosely hang on one of the fingers on each of your hands, and then collide the two bangles very lightly. If the bracelets are made from jade, the sound should have a very clear, pleasant and higher pitch sound than the sound produced by two pieces of glass or other synthetic substances.

7) The method which delivers the most accuracy is to break the piece. If the piece is made from jade, then the inside should be composed by tiny mineral particles you can see. However, if it is made from glass, the broken surface should be smooth with glassy pattern.

From: LuMingTang