Ten characteristics of B-grade jadeite identification

1/ Gloss

After polishing, the surface of A-grade jadeite is as smooth as a mirror, has strong reflectivity and a glassy luster. After being soaked in strong acid and alkali, B-grade jadeite has a loose structure, with corrosion pits on the surface, diffuse reflection, and a pockmarked luster. After being filled with glue, the surface of B-grade jadeite has a resin luster and lacks spirituality. After being filled with glue and then polished, resin luster spots can still be seen in the filled pits, and the overall appearance is a mixture of resin luster and glass luster.

2/ Color

Grade A jade has natural color and layered texture. The color of B-grade jadeite is formed after the original color is removed, and it is bright yellowish. Because the structure of jade is destroyed and its internal optical properties have changed, the color distribution of B-grade jade has no sense of hierarchy and appears to be a uniform color.

3/ Structure

The raw materials for making B-grade jadeite are generally jadeite with more impurities and loose structure. After being soaked and corroded by strong acids and alkalis, some substances are brought out and dissolution occurs on the surface and inside along the mineral crystals, resulting in internal interconnected cracks and surface water channels. The internal cracks are jagged tensile cracks. Under transmitted light conditions, the criss-crossing cracks inside are visible, which seriously affect the permeability. Under reflective conditions, the dissolution pits or reticulations on the surface are clearly visible, and the original glass luster of the jade is lost.

4/ Bubbles

Residual bubbles may be seen in the colloid on the surface or in the cracks of B-grade jadeite that is filled with glue.

5/ Impurities

When A-grade jade is observed under magnification, yellow, brown, and black impurities may sometimes be seen; B-grade jade is relatively pure and has no impurities.

6/ Fluorescent

B-grade jadeite has a uniform medium-grade yellow-green and blue-green fluorescence.

7/ Thermal reaction
Grade A jadeite will not melt below 800℃, while grade B jadeite filled with glue will carbonize after being heated to 200-300℃.

8/ Density
The density of grade A jade is greater than that of grade B jade, so generally speaking, of two pieces of jade with the same volume, the grade A one is heavier than the grade B one.

9/ Sound

Hang the jadeite with a rope, then knock on the jadeite with other jade accessories and listen to the sound the jadeite makes. If the sound is dull and hoarse, it means it is B-grade jadeite. On the contrary, if the sound is loud, it means it is A-grade jadeite.

10/ Rift
After being dissolve by strong acid, the width and depth of the original cracks in jadeite increase, as do the tortuosity of its boundaries and more branches appear. Moreover, after B-grade jadeite is filled with glue, it has different physical and chemical properties from the original mineral cement of jadeite, its reflection is extremely weak, and it appears cloudy under a high-power microscope.

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