Generally, amethyst and citrine crystal of high value species. Two further classification is according to the shade of the color, darker for a-level, slightly lighter for b-class. Higher generally darker, but dark as the standard. Colors include two, one is the color of the Crystal itself, another is the color of internal inclusions. Crystal its colour: bright, pure, distributed uniformly, not too deep or too shallow, such as Australian jade, chalcedony, Amethyst, Blue Topaz, its price is high. Color of colorless crystals containing inclusions and prices are high, such as titanium Crystal, green ghost, red hair.
Purple Crystal with slight clouds, dark purple, crystal clear is the top grade.
In accordance with the transparency indicator, crystal clear, high price, good transparent Crystal manufactured products pure, shining bright. Transparent Crystal can raise the bright colors, no spiritual or is dull. Optical crystal requires full transparency, unique Crystal, free of impurities. Crystal technology requires less transparent, less cracking, defective. Melting crystal transparency requirement, may have more cracks. Decreases the value of the three, melting Crystal only as a crystal glass melting raw materials. In Crystal technology, large Crystal, Crystal glasses and engraved luxury crafts can be used to do, and thus higher prices.