The gem do not request the operation or the stone material quality in the processing process according to the standard is not good, either the accessory material is not good, either the equipment precision is not high, will cause the product flaw, will form the second quality item, will become the scrap rock, the common flaw and the origin will be as follows: 1, Mongolia: Product not in the least gloss, a piece of white. Because does not have polishing or does not polish the formation. 2, air bubble, impurity: The gem interior has enclosures and so on air bubble, impurity, is produces in the stone material process to form. 3, crack stone: Including collapses, the crack, rottenly and so on performance formations, generally is the burr operates improper or the quarrying semifinished product operation not, when forms, the internal stress causes the crack the situation to be rarer (refers to first lecture of elementary knowledge). 4, the size do not work as: The gem request particle size, long, the width error does not surpass 0.05MM, exceeding is improper for the size, is also called the size not to permit. The special request exception, some Pu currency request error does not surpass 0.1MM then.nearby 5, shovel: Side the gem keeps (waist line) to be clearly discernible, thickness is even, on the one hand the entire strip might some section on the other hand abrasion namely for the shovel nearby, the boundless part cutting edge equally was likely sharp. Generally is because of turns the stone not just or nearby the circle forms excessively. 6, crooked point: The gem bottom point should reside in the gem central location, the deviation is the crooked point, generally is because turns the stone not to be positive, side forms the thickened-edge thin result. 7, Mongolia: The gem requests to assume the Jin'gang, Asia adamantine luster, or the partial pan gloss is insufficient, assumes the fog shape, the iron grey is Mongolia completely. Generally is because polishing is not good creates. 8, Sha Jie: Between the pan and the pan hands over in the middle of the wiring or the pan has a line not to have polishing, assumes the white streak, the brown streak, namely for sand. Creates because of polishing. 9, sand hole: In pan, punctual, assumes the black, brown, the white, unclean forms because of polishing, also calls the hemp the spot. 10, leakage of light: The gem request reflects once more after the pavilion department process reflects completely from the crown department injection's optical fiber from the crown, if the optical fiber refracts in the pavilion department, but is not reflects from the crown department is called the leakage of light, said popularly is the optical fiber leaves out in the pavilion department. Is too small because of the pavilion department angle, the pavilion department insufficiently high forms.