Color: For any gem, color is very important, and crystals are no exception. If the crystals are color, such as pink crystals, yellow crystals, amethyst, etc., the highest criterion for color evaluation is bright and touching, without gray, black, brown and other colors. Such as pink crystal, the color is better; the amethyst, the color requires the color to be fresh purple, pure and not black; the yellow crystal, the color is required not to contain green, lemon color, and golden orange color is better. For hair crystals, the color of the crystal is also very important. The blond crystal of the same hair, the crystal is completely colorless (white crystal) and the crystal is slightly tea, and the visual perception of the naked eye is also different, so the price of the former will be higher than the latter.
Clearness: Crystal and high -end gems are very different. High -end gems are rare, so people generally do not demand the clarity of high -end gems. The production of crystal is really amazing, so usually people ask the crystal clarity as better, and try to avoid obvious crystals with obvious internal contents.
Impurities: If there is a legendary figure in the internal impurities of the crystal, the value of the characters, such as the Buddha, constellation, and zodiac may be higher than the crystal of the same color and clarity.
The state has not provided a specific standard for grade to natural crystal. The crystal varieties are complicated, and each variety has his different judgment standards.
