Jade history in our country has a long history. The ancients, according to the theory of five elements, distributed the five-colored jade by the four directions and the center: East is green, South is red, West is white, North is black, and the center is yellow, with no record of blue. The color of He Shi Bi, which Emperor Qin Shi Huang used to carve the Imperial Seal, was described as "green like blue, warm and lustrous", which shows how rare the blue jade is.