Optimization of Jade and Identification of True and Fake Jade

(1) Baking:

Baking color is actually a method of using heat treatment to make jade appear beautiful red. The process of changing the original brown or yellow jadeite surface into liver red through fire, turning it into red jadeite with good sales appearance, is called baking color.

Many friends mistake baked jadeite for dyed jadeite. Dyed jadeite is generally injected with glue, while baked jadeite does not go through the glue injection process, making it more difficult to identify baked jadeite. Baked jadeite, the so-called "baking" is to subject jadeite to high-temperature heat treatment to improve its color. It is mainly to take some low-grade jadeite that originally has a yellowish-brown tone (containing limonite), and subject it to high-temperature heating (usually 200°C) to evaporate the moisture in the limonite to form vermilion hematite, and turn the yellowish-brown part of the jadeite into red, so as to obtain the more valuable red jadeite.

The "baked" color is permanent and almost indistinguishable. Because the formation mechanism of baked red jadeite is almost the same as that of red jadeite formed in nature, the only difference is that the baking process is completed through rapid transformation under artificial environment. It can be said that it only simulates natural conditions. Even the certificate issued by a professional inspection agency will not have any special note that it is considered as natural A-grade goods. Because according to the "National Standard for Jewelry and Jade" promulgated by our country, heat-treated gemstones (including jadeite) are considered simply "optimized" and classified as natural gemstones.

Some jadeite that is yellowish-gray in color and not bright red can be made more red by high-temperature baking. However, after baking, the toughness of jade decreases and its brittleness increases. As the number of microcracks increases, the sound will be hoarser when tapped. Alternatively, infrared spectroscopy may be performed, which will reveal the lack of adsorbed water due to baking.

Note: Green jadeite cannot be treated with baking.

(2) Coating treatment:

Coated jade is also called "dressed jade" or "color-coated jade". The production of coated jade is to select a transparent but colorless jade ring face and coat it with a thin film (gelatin) on its surface. Coated jade looks beautiful and lustrous, like high-end jade jewelry, and is highly camouflaged and deceptive.

The characteristics of coated products are that the green color is evenly distributed and full of color, the color on the front and back are the same, and at the same time, it does not have the color distribution characteristics of natural jadeite which is spotted, striped, veiny, or filamentous.

The surface of natural jade is very smooth and feels icy to the touch, but since coated jade is coated with a layer of gelatin, when you rub it with your hands you will find that it is not as smooth as natural jade and feels sticky. If observed with a magnifying glass or microscope, you can see that the green color is only attached to the surface of the jade piece and not from the inside. Due to the low hardness of the membrane, very fine friction scratches are often seen on the membrane. Natural products do not have this phenomenon.

(3) Identification of B-grade, C-grade, B+C-grade and D-grade jadeite:

B-grade jade refers to jade that has been soaked in strong acid to remove impurities and then filled with glue. B-grade jade is also called "shower" jade, and its texture is fake. After being soaked in strong acid, the dirty impurities in jade are soaked away, but at the same time the texture of the jade is completely destroyed. It does not have the toughness of jade, and it is soft and full of gaps. In order to make it invisible on the surface, transparent silicone is added to the gaps. So B-grade jadeite looks very beautiful in color and has a very transparent texture, but its price is very low. The reason why many people accidentally buy B-goods is that B-goods often look good and cheap. However, B-grade jade cannot stand the test of time. Generally, after a few years, the silicone will oxidize and the jade will become unrecognizable. Therefore, B-grade jade is not real but fake. To identify B-grade jadeite, turn the jadeite under the light and find the angle where you can clearly see the reflection from the surface of the jadeite. If you look closely, you can see that there are many pits and pockmarks on the surface of the B-grade jadeite, which are formed when the silicone on the surface is weathered, abraded and peeled off. In addition, the luster of B-grade jade is different from that of A-grade jade. A-grade jade has a dense structure and a glassy luster on the surface. Because B-grade jade is injected with glue, its surface exudes an oily luster.

C-grade jade is jade that has been artificially dyed. Color is added to the originally colorless jade. Its color is fake and it is also a fake. There are many methods of dyeing. Most of them are to heat the jade first to increase the cracks between the crystal particles, and then partially place it in the dye to allow the color to enter the jade along the cracks. The dyed colors are mostly green, purple, yellow, and red. When looking at C-grade jadeite, hold it up to the light and look carefully at the color distribution of the jadeite. You can often see that the color is distributed along the cracks. This color distribution is unnatural and looks very much like capillaries. When you see this situation, you can conclude that the color is not naturally present in the jade, but has entered from the outside. In addition, the dyed color has no color roots and often floats on the surface of the jade. The color is also "dead" and "dull", and lacks vitality.

B+C goods are a combination of B goods and C goods. They have the same characteristics as both, including acid washing and dyeing, and their identification methods are the same as those for B goods and C goods.

D-grade jade refers to the material that is not jade but is disguised as jade. Some are glass and worthless. Some are jade or quartz that have certain value in themselves, but are counterfeited as jadeite because jadeite is more valuable. These are called D-grade jadeite. Common imitations include jasper among nephrite jade, uranium rock among serpentine jade, aventurine, Australian jade, Malayan jade among quartzite jade, Dushan jade among feldspar jade, and so on.

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