Jade’s “Luminescence” and “Fluorescence”

Before starting today's jade class, Cuicui would like to test you first. Please look at the question.

Question: In jadeite, do “luminescence” and “fluorescence” mean the same thing?

A. Yes

B. No

Analysis: If your answer is option A, it means that the following content will be very helpful to you; if your answer is option B, it means that you already have a certain foundation in the content of jadeite, and you can continue to gain a deeper understanding through the following content.

Through the above questions, I believe everyone has already known that the "fluorescence" and "fluorescence" in jade are not the same concept. So what exactly do the "fluorescence" and "fluorescence" in jade mean?

The “glow” of jadeite

The concept of jadeite "fluorescence"

In the jade market, you should often hear words like "This piece of jade is of good quality and it has a 'fluoresce'!" The "fluoresce" that everyone refers to actually refers to a unique optical phenomenon in jade. This phenomenon generally occurs in earrings, necklaces, pendants and bracelets made of high-quality colorless jadeite or Qingshui or Blue Water jadeite.

When shaking the jade, we can observe a soft, white, hazy white light. Some documents describe it as the feeling of looking at the moon under thin clouds at night. Some documents also mention that "qiying" refers to a layer of faint light that emanates from the inside of transparent jade when observed with the naked eye under the illumination of light. In the book "Image Jadeology" written by Ma Chongyang, this phenomenon is called "live light". The book mentions that "when jade is cut into a curved surface or round bracelet, a bright light band can be seen on the curved surface with the naked eye, and it moves with the rotation of the jade and the change of light direction, so it is called 'live light'."

The “glow” of jadeite

The reason why jadeite produces "fluorescence"

If you often visit the jade market, you should find it easy to discover that the "fluorescence" of jade does not appear in all jade, but mainly appears in jade products with good quality and high fullness. Experts and scholars in the industry have different explanations for the reasons for the "fluorescence" of jadeite. Some experts and scholars believe that the "fluorescence" is mainly produced by the combined effects of jade's diffuse reflection and focusing effects on light. Cuicui mentioned in a previous article that jade is mainly composed of an aggregate of jadeite minerals. Therefore, when light shines into the interior of jade, the jadeite mineral particles, gaps between crystals and tiny cracks will cause the light to be refracted and diffused. When jade reaches a certain level of transparency, the refracted and diffused light will be reflected along certain parts of the jade and re-enter our eyes, which forms the "fluorescence" of jade that we see.

Some experts also believe that the "fluorescence" is caused by the fact that jade is composed of a dense aggregate of tiny jadeite crystals, which produces differences in hardness in different directions, thus causing microwave-like fluctuations on the polished surface of jade. When the transparency of jade is relatively good, part of the light is transmitted from the air to the polished surface of jade. The micro-wave-like undulations on the surface of jade will produce part of reflected light, forming a reflection point; the other part of the light enters the interior of jade, and before returning from the dense medium (inside the jade) to the sparse medium (air), it is diffusely reflected inside the jade through the micro-wave-like undulations on the surface of jade, and forms hazy white light spots with the refraction between the jadeite grains, which is the "fluorescein".

The "fluorescence" will move with the rotation of the jade and the change of light direction.

Factors affecting jadeite's "fluorescence"

According to research and verification by experts and scholars in the industry, the intensity of the "fluorescence" in jade and the intensity of the diffuse reflection produced are closely related to the transparency of jade, the particle size of the jadeite mineral aggregates in jade, and the degree of bonding. If the jade mineral particles are coarse, the structure is loose, and the light transmittance is weak, the jade "fluorescence" will be relatively weak, or even invisible; if the jade mineral particles are fine, the structure is tight, and there is more incident light, the jade "fluorescence" will be stronger and more obvious.

The "fluorescence" will move with the rotation of the jade and the change of light direction. At this time, we will find that when the light is strong, the jade with "fluorescence" often gives people a feeling of lack of transparency, but this has nothing to do with the size of the jade particles themselves, but is caused by the optical phenomenon produced by the jade.

When the intensity of light changes, the intensity of jadeite's "fluorescence" also changes, and jadeite will also show different transparencies.

In addition, the appearance of jade "fluorescence" is also related to the focusing effect of jade products. In jade products with relatively good transparency, the full curvature of the jade surface will cause the incoming light to achieve a focusing effect, similar to the focusing effect of a convex lens, thereby making the jade "fluorescence" more concentrated. Therefore , when the carving curvature of jade products is better, the focusing effect of jade will be better, and the "fluorescence" of jade will be more obvious; but when the jade is relatively flat and thin, and the carving curvature is not enough, because it cannot produce the focusing effect, the "fluorescence" of jade will not be obvious. This involves some more special carving techniques in the current jade market, commonly known as "water adjustment" in the jade industry. That is, by carving the back of the jade pendant or ring face into an arc-shaped convex surface to enhance the "fluorescence" effect of jade, so that the final product can have a better visual presentation.

In general, the "fluorescence" of jade is closely related to its transparency, texture, carving craftsmanship and other characteristics, and it is of certain significance for the evaluation and identification of jade quality.

The “Fluorescence” of Jadeite

The concept of "fluorescence"

In academia, the term "fluorescence" refers to the property of a substance to emit visible light when it is excited by higher energy radiation. In the identification and testing of jewelry, ultraviolet fluorescent lamps are often used to detect the fluorescence of various gemstones. Whether the gemstone shows fluorescent characteristics is closely related to whether it has been artificially processed. Therefore, the "fluorescence" of gemstones is one of the important characteristics for identifying and evaluating gemstones.

The “Fluorescence” of Jadeite

Through research by experts and scholars, we know that natural jade has basically no fluorescence, especially green, dark green, black and red jade, which have no fluorescent characteristics under ultraviolet fluorescence. Only a small amount of white jade will have a weak orange fluorescence. However, after being waxed (optimized), the jade will have a weaker blue-white fluorescence. If the structure of the jade is not dense enough and more wax is immersed in the jade, the fluorescence characteristics of the jade under ultraviolet fluorescence will also be enhanced.

Fluorescence characteristics of B-grade jadeite under ultraviolet fluorescent light

In addition, jadeite that has been treated with acid washing and filling with glue (jadeite B goods) or acid washing, filling with glue and dyeing (jadeite B+C goods) will have strong fluorescence under ultraviolet fluorescence, and some jadeite that has been dyed (jadeite C goods) will have strong fluorescence. It can be seen from this that the application of "fluorescence" is also of great significance for the identification and evaluation of jadeite.

Fluorescence characteristics of B+C grade jadeite under outdoor fluorescent light

Although the pronunciations of jade "fluorescence" and "fluorescence" are the same, their meanings are very different. Jade "fluorescence" is a new term created by the folk jade market after long-term observation and practice. Nowadays, more and more jade lovers are beginning to like jade with good "quality" and "good water". "Fluorescence" adds more beauty to jade, and also injects more fun into our understanding of jade.

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