1, texture
Requirements for high-quality Hetian jade: dense, uniform, delicate, translucent or slightly transparent, no cracks or less cracks, less clean impurities and fewer defects; And hetian jade with low quality has less requirements for texture. Hetian jade can be divided into four grades according to its texture: super grade, first grade, second grade and third grade.
Super grade: fine and even texture, strong grease luster, translucent or slightly transparent, basically free of cracks, impurities and defects. Grade I: fine texture, strong grease luster, translucent or slightly transparent, with cracks, impurities and defects less than 10%.
Grade II: fine texture, weak grease luster, poor or too transparent, with less than 30% cracks, impurities and defects. Grade 3: rough texture, waxy luster, poor transparency, cracks, impurities and more than 30% defects.
2. color?
Hetian jade is divided into eight categories by color. Generally speaking, white jade, white jade and topaz with suet are the best, followed by jasper and jet, followed by sugar jade, sapphire and sapphire. Except for white jade, the other seven categories all require observation and analysis of colors from four aspects: hue, concentration, purity and uniformity, and the hue of colors should be positive, not partial and not variegated.
The evaluation of concentration is about color saturation, which needs appropriate shade; The evaluation of purity is generally that the purer the better, the worse the color is, for example, green, positive green is the best, gray green and blue-green are all poor; Uniformity requires uniform colors. In addition, Hetian jade often has more than two colors, such as leather and sugar. If the colors are properly matched and the beautiful colors are ingenious or novel, it can add color to the work and even double its value.
3. Gloss and transparency
Hetian jade can be divided into oil luster, glass luster and wax luster, among which oil luster is the best, which can make jade appear moist. Followed by glass luster, wax luster is not good. The best hetian jade is different from jadeite, and it is mostly oily and shiny. The gloss is better if the oil is clear.
Hetian jade is generally opaque, mostly translucent to opaque, which can be divided into three grades: translucent, slightly transparent and opaque. Hetian jade is translucent and slightly transparent. If it is waxy luster, poor transparency or too transparent, it is second.
4. Fragmented (weight) raw materials are fragmented to some extent. The bigger, the harder, and the higher the value. Hetian jade with the same texture and color has high value, while small jade has low value.
Extended data
Compared with nephrite in other areas at home and abroad, Hetian jade has more colors and formed its own series. Secondly, Hetian jade has rare white jade in the world, especially the white jade with suet color, which is unique to Hetian jade and of high value; Thirdly, Hetian jade has leather color. Many jadeites in the world have skin color, but they are not as beautiful as Hetian jade. China attached great importance to the color of Hetian jade in ancient times. It is not only an important symbol of quality, but also contains certain ideological connotation.
Influenced by the theory of five elements, the ancients distributed five-color jade in four directions and centers, with blue in the east, red in the south, white in the west, black in the north and yellow in the center. In ancient times, blue, red, yellow, white and black were positive colors, and others were intermediate colors, so jade was also divided into five colors. But Hetian jade actually has only four main colors: white, blue, ink and yellow. In addition, Kunlun Mountain and Altun Mountain also produce jasper.
Among Hetian jade, white jade is the most precious, and the best white jade is suet white jade, which is the top grade of jade. Sheep fat white jade is white, transparent, delicate and moist. Because topaz is rarely produced, pure and moist chicken oil is yellow, and its value is not under white jade.