Goods 1 and a refer to natural jadeite without artificial treatment. A goods are pure natural jadeite, only carved and polished. There is no chemical treatment, no artificial forgery such as high temperature and high pressure. It is a natural color, which is called "positive color" or "true color" without dyeing or electric color.
Visually, the texture is delicate, the color is soft and the stone lines are obvious; Slight impact, crisp and pleasant voice; It feels very heavy and is obviously different from other stones. It is characterized by a density of 3.32-3.34g/cm3, a refractive index of 1.66, a glass luster, a fiber interwoven structure under enlarged observation, and no fluorescence under ultraviolet lamp.
2. Goods B are jadeite which is soaked and corroded by strong acid to remove impurities, and then cracks are filled with resin or glue, so that the species, water and color are greatly improved. The English word bathe means "washing", and the initial letter is B. Therefore, washed jadeites are collectively referred to as "B goods" and "bleached goods".
Of course, jadeite is not washed with water, but soaked with strong acid to corrode and dissolve impurities and stains, making it clear and bright. The structure of jadeite washed by strong acid is loose, and the cracks after acid etching must be filled. The common method is to inject transparent resin by vacuum negative pressure method. The refractive index of this resin is close to that of jadeite, and it is almost the same as that of high-grade jadeite after polishing.
3. Goods C are dyed jadeite, which belongs to true jade and false color. C- jadeite: the customary name for artificially dyed jadeite. Although the name began after B-grade jadeite, the dyeing treatment of jadeite originated very early, probably from the beginning of the 20th century.
But the dye used in the early days is an inorganic chromium salt, and the jadeite dyed with it will appear red (purple-dark red) under the Charles filter. Since the 1980s, people have switched to organic dyes, and jadeite dyed with it will no longer appear red under the filter.
For this kind of C-grade jadeite, it can only be identified by more careful observation. At this time, you can notice that its color has the feeling of floating on the surface. More importantly, under the magnifying glass, you can see that the colors are distributed along the edges or cracks of the particles like cobwebs, rather than starting from the mineral particles themselves.
C the color of jadeite generally does not last long, especially in the sun. Generally, it lasts for one or two years, and it will fade after four or five years. In addition, modern C jadeite is not only dyed green, but also dyed red and purple.
Extended data:
To identify jadeite in life, we need the following five steps: weighing, looking, rowing, listening and touching.
1, weight: jadeite has a relatively large proportion. If you put the jade in your hand and move it up and down a few times, there will be a heavy feeling that your hand is pressed down. It may be real jade. The treated jade will be a light feeling in your hand, and there will be no heavy pressure. For medium-sized jadeite, this is a good identification method.
2. Look at the luster: the surface of natural jadeite has bright glass or grease luster, while the surface of treated jadeite will be dull or rubbery.
3, scratch hardness: the hardness of jade is very high. When scraping or wiping its surface with a sharp nail or knife, Cui Zhen will have a slippery feeling and will not leave any scratches; However, the treated jadeite will leave obvious scratches on its surface because its structure has been destroyed.
4. Listen to the sound: hang the jade with a rope, then tap it gently with a glass rod, and the natural jade will make a crisp and pleasant sound; The sound of dealing with knocking jade is very dull.
5, feel: natural jade heat transfer and heat dissipation is fast, stick it on the face or put it on the back of the hand, and it will feel cold in a short time; In addition, natural jadeite feels delicate and smooth, while the treated jadeite surface will have a rough feeling.
References:
People's Network-When the old jadeite meets the new standard
References:
People's Network-Experts teach you how to tell the true and false jadeite?