What are A-grade and B-grade jadeite and how to identify them?

Grade A Jade: Pure natural jade, which has not undergone any physical or chemical treatment except mechanical processing. It has a smooth and delicate surface, good glass luster, and its internal structure has not been corroded or damaged. It is natural jade that has not undergone any artificial improvement treatment, and its color and transparency are genuine.

B-grade jadeite: Jadeite that has been soaked in acid solution to remove impurities and discolorations in order to improve its transparency, clarity and the brilliance of its original green color. Regardless of whether it is injected with glue, it is B-grade jadeite, that is, the color is real but the transparency is fake. Its internal structure is damaged, and there are obvious cracks and dents on the surface, which will affect the refraction of light. The biggest difference between it and A-grade jadeite is its gloss. Generally, it is processed using raw materials with coarser grains, poorer texture, and discolorations such as yellow-brown, black and gray.

The process flow of B-grade jadeite: material selection, cutting, acid washing and bleaching, filling with glue, and consolidation. So how do you identify B-grade jadeite?

1. There will be acid-etched reticulation or glue-filled pits on the surface. Because the hardness of the resin glue filled in it is relatively low, concave grooves will be formed during cutting and polishing. They are distributed along the boundaries of the particles and look like reticulated cracks on dry soil. If the acid pickling is too strong or the bonding treatment is not ideal, a large number of sand holes will appear on the polished surface.

2. The knocking sound of some B-grade jadeite is mostly dull and hoarse, not crisp enough, and different from the natural one.

3. Acid-etched and glue-filled cracks usually have an oily luster and are very clear open cracks on the surface, but the parts extending to the interior are not obvious and do not block the passage of light. The healed cracks in natural jade are very clear on the inside.

4. Observe the internal structure of the jadeite. The boundaries between the acid-washed grains are blurred, especially for the coarse-grained B-grade jadeite.

5. The base color is clean and free of impurities. After acid washing and bleaching, the impurities are dissolved, the yellow base and dirty base are removed, and the white part is carefully observed, without impurities and gray-yellow components.

6. The density of jadeite will be significantly reduced after acid washing and filling with glue, especially the jadeite that has been treated with the so-called "Big B" treatment (the relative density of natural jadeite is 3.33), which can be checked through the appraisal certificate.