9 ways to identify jadeite

Here are 9 methods to identify jadeite. I hope it will be helpful to you.

1. Gloss. After being soaked in strong acid and alkali, the structure of jade becomes loose, and before filling, corrosion pits appear on the surface, causing diffuse reflection and weakening the luster. After adding organic fillers such as resin or plastic, jade often has resin luster, waxy luster, or a mixture of glass luster with resin luster and waxy luster.

2. Color. Since the structure of jade is destroyed, the original optical properties are also changed, so the color distribution of "B-grade expanded jade" has no sense of hierarchy. Although the green color of jade treated by this method is still the original color, after being soaked in acidic solution, the base becomes white, the green distribution is more floating, and the original color orientation is also destroyed, which looks very unnatural.

3. Structure. When jade is soaked and corroded by strong acids and alkalis, some substances are brought in and out, causing dissolution along the mineral crystals on the surface and inside, resulting in internal interconnected cracks. Under transmitted light, the crisscrossing cracks inside can be seen. Under reflected light conditions, the surface dissolution pits or spider-web-like patterns are clearly visible.

4. Surface characteristics. Jadeite treated by this method has obvious grooves at the original cracks due to the large difference in hardness between the filling material and the jadeite itself. The filling material is obviously lower than the two sides, and many cracks form criss-crossing ditches. Cementation or residual bubbles can be seen in the larger "ditches". The surface of jadeite treated with bleaching and filling using recent better processing technology is very smooth, without the above phenomenon, and requires more careful observation and measurement.

5. Density and refractive index. Most jadeite that has been bleached and filled has a slightly lower density and refractive index. The density is 3.00~3.43g/cm, and the refractive index is about 1.65 (point measurement). However, due to the complex mineral composition of jade, the density and refractive index values ​​of some natural jade may be low. Therefore, the density and refractive index can only be used as reference data and usually cannot be used as a basis for determining whether jade has been filled.

6. Fluorescence. There is no or weak to strong ultraviolet fluorescence, and the fluorescence distribution is uniform or mottled. Most of the early "B-grade" jadeite has fluorescence. Short wave: weak, yellow-green or blue-green (blue-white); long wave: medium to strong, yellow-green or blue-white. However, jadeite treated with this method recently usually has weak or no fluorescence.

7. Zoom in and check. Magnified Inspection Magnified inspection is an effective method for identifying this type of treated jadeite. It is divided into surface observation and internal observation. Use transmitted light to observe the internal structure of jadeite. The jadeite that has been bleached and filled has a loose structure, blurred boundaries between the grains, broken grains, and discontinuous cleavage.

8. Thermal reaction. When "B-grade" jade is heated to 200-300℃, the gum will carbonize.

9. Tap response. The structure of jadeite is destroyed after bleaching and filling, and the space between the mineral particles is filled with colloid. Therefore, it will make a dull sound when tapped gently, which is significantly different from the crisp sound of natural jade (this method is mainly suitable for identifying jade bracelets).

fcgc66

fcpf18