gate also for code Birkenau, Manau, horse brain, etc., is a kind of jade pith minerals, often mixed with egg white stone and hidden crystal quartz stripes block, hardness 6.5-7 degrees, the proportion of 2.65, color is quite hierarchical. Having translucent or opaque. The original form tripartite crystal system. Often a dense block and form a variety of structures, such as breast-shaped, grape-like, nodule-like, common for the concentric circular structure. With different color composition of the jade pith, usually have, green, red, yellow, brown, white and many other colors. According to the pattern and impurities can be divided into onyx, tangled silk agate, moss agate, Castle Agate and so on. Used as a plaything, ornamental object, ornament, or pet. Ancient funerary objects often can be seen in string of agate ball.