Black has stable, grave, classical, charm, noble, mystery, represents the low-key, implicative and restrained trait. 


Black agate
Appearance features: color gray green, blue ribbon pattern, contains more impurity. Some head is better, for the translucent.
Diamond
Diamonds are the existing materials thermal conductivity in the fastest, if your CPU has a diamond do radiator, then... You must have been mad natural material, diamond is the hardest, but theoretical calculated that CN3 than diamond to hard, it is a pity.
Flash ShiYu

Appearance features: head foot, translucent above. Grease to vitreous luster. Green is uniform. Pole and high-grade jade interblend.


Siliceous rock jade
Calcium aluminum garnet ShiYu
Appearance features: head is poorer, slightly transparent to translucent. Green is mottled or banded. Hardness and feel similar with jade.


The most common on the market a fake jade jade. The personage inside course of study known as "water foam jade".
Jewerly
Sodium long ShiYu