1st, color Most guides the people to pay attention is the gem that bright with many colors, the colorful color. The different gem has the different color, even if the same color, in the characteristic, the shape is impossible to be completely same, often has the depth, the shade difference. For example, with is the chlorosapphire, generally, grandmother's green color is the pure green, the jadeite color is the colorful green. The gem compares with other material's color also has the following characteristic. First, the gem color is one kind of spot seizes esthetic sense many gems for person's feeling to be extremely easy rottenly to receive each kind of different photo source the influence, changes frequently along with the photo source change. Presents its glittering and translucent carving, the bright with many colors effect, specially under glare, is unable to identify them colored nearly firmly. Next, the gem color is the decoration color the category, it and the gem material quality merge into one organic whole. Once the material quality changed, then the color psychologic effect has also had the change along with it. For example, one kind of red color, appears in the diamond is one kind of radiant US similarly; Appears in the ruby is one kind of magnificent US, appears on the jade is one kind gentle and implicit US ......