How to identify A-grade jadeite? How to distinguish B goods and C goods?

Grade A jade is pure natural jade that has only been carved and polished. It has not undergone any chemical treatment, nor has it been artificially falsified by high heat, high pressure, etc. It is a natural color, not dyed or electroplated, and is called "true color" or "real color". Observed with the naked eye, the texture is delicate, the color is soft, and the stone patterns are obvious; when lightly bumped, it makes a crisp and pleasant sound; it feels heavy in the hand, which is clearly different from other stones.

To identify A-grade jadeite, you must first have the identification certificate.

The back of the certificate contains some relevant information about the item being identified:

1. Certificate number, you can check whether the number on the item is consistent with the number on the certificate (there is also the possibility of inconsistency as mentioned above)

2. Test conclusion: usually written as jadeite, some even have a note behind: A grade (you can't relax after seeing this, you still need to look at the following things)

3. Mass (weight of the item)

4. Shape of bracelet or pendant (bracelet will usually be marked as round, flat or imperial)

5. Size (bracelets are generally measured by inner diameter, width, and thickness; pendants are generally measured by length, width, and thickness)

6. Color; (Some informal ones will have a note at the end: "ice taste", "ice type" and so on.) Generally, formal appraisal agencies will not help you identify the color of the jade, so be careful with any notes.

7. Refractive index: Generally, single crystal jadeite has three different refractive indices. However, jadeite is generally composed of very fine jadeite particles, so the refractive index cannot be accurately measured, and it is even more difficult to identify it using the birefringence index (so some with birefringence are generally filled in as unmeasurable at the end). Therefore, in actual measurement, the approximate refractive index or average refractive index is generally used to represent the characteristics of jadeite. The general identification result is 1.66, which is a quantitative data that distinguishes jadeite from other jadeite.

8. Density: Generally, the density of jadeite is above 3.33, so it slowly sinks in diiodomethane. Using the hydrostatic method to determine the density of jadeite is also an important identification method.

9. Magnify and inspect; Jadeite is generally polycrystalline jadeite with a fibrous interwoven structure inside, so the measurement results are mostly: fibrous interwoven crystalline or granular structure. The most important point is that there is no filling phenomenon, which means that the jadeite is not filled with any other substance. Don't be too happy after reading the above test results, because the last and most important item is: spectral detection.

10. Spectral test; the general result is the 437nm absorption line. Why is this an important item?! In my article "Hoo-Hoo Talks about Experience", I mentioned a kind of jade craftsmanship that also belongs to the A-grade range. Taking a small bath: The bracelet is not very beautiful after being processed from raw materials. Some bracelets of poor quality have obvious surface particles and the visual effect is not very good! Therefore, most of them use mild acetic acid to soak the semi-finished products for a few hours, so that some oil stains on the processing can be removed. This will not cause much damage to the structure of the jade. The damage is only on the surface and is relatively minor. As for wax or oil immersion, it only makes the surface of the bracelet flat and smooth, increasing transparency and beauty! The interior of the jade treated in this way is not damaged, and it has always been in the A-grade range! Taking a small bath is more harmful. If the jade is not worn for a long time, the water will be lost and the jade will crack, and the problems that were originally covered up will appear! Generally, the bracelets dipped in wax will not show anything in the previous tests! But in the last one: the spectrum test is very obvious! Most of the test results of wax dipped are: peak spectrum wax absorption! Everyone should pay attention to this!

At the end, it is usually written: the name and date of the inspector, reviewer, and approver! If the above are normal, it can be concluded that the jade has not been processed! In that case, you can buy it with confidence. Some certificates are written more simply, with only numbers, conclusions, weights, etc.! As long as such certificates are issued by an authoritative organization, you can buy them with confidence!

When you start watching it yourself, pay attention to the following points.

color

The colors of B-grade and C-grade goods are unnatural. The colors in the gaps are particularly dark and do not match the surrounding colors. The colors of A-grade goods are dense.

Jade B goods

structure

Under the light, the structure of A-grade products is clear, while that of B-grade products is relatively blurry. For colored jadeite, A-grade jadeite has a dense and not loose structure, while B-grade and C-grade jadeite has a scattered structure, giving people a floating feeling.

weight

A-grade products are slightly heavier and feel solid in the hand.

sound

If you hang the jewelry in the air with a thin thread such as hair, and gently hit it with agate or A-grade jadeite, it will produce a very melodious, clear and echoing sound. The crisper and more pleasant the sound is, the more metallic it has. The sound of B-grade jadeite is dull, not crisp, and not pleasant.

Impurities

Some of the impurities in B and C goods are processed and filled with glue to make them float.

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