As the saying goes, "People have thousands of faces, and jade has thousands of faces", which shows how many varieties of jade there are. Green is the essence of jade. Jade can be divided into different types according to its hue, saturation and distribution. This article briefly introduces the color of jade and the method of jade color classification. Interested friends can learn about it!

How to classify jade by color?

Green is the essence of jade. According to the hue, saturation and distribution of jadeite green, jadeite can be divided into:

1. Divide by color tone

(1) Gem green: including emerald green, emerald green, katydid green and other colors. The green color does not contain any color cast, and is pure, bright, evenly distributed, transparent to translucent, and has a fine texture. It is a precious variety of jade.

(2) Yellowish green: The hue is medium, with a slight hint of yellow in the green, second only to emerald green. It can also be divided into: Huangyang Green, Onion Heart Green, Parrot Green, Bean Green and other varieties. The jade is relatively coarse and belongs to mid-range jadeite.

(3) Bluish-green: The color tone is darker, with a slight blue tint in the green, and it is translucent. It is generally mid-range jadeite. It can also be divided into: blue water green, spinach green, melon skin green, blue-green, green oil green and other colors.

(4) Gray-black-green: The color is not bright, the tone is dark, the green is mixed with gray-black, and the transparency is poor. Generally low-grade jadeite. It can also be divided into: dark green, oily green, toad green, gray-green and other colors.

2. Classification by green saturation (brightness)

(1) Bright green: transparent or translucent, pure green, uniform, rich and bright color. When the color is darker, it is old bright green, which is a precious variety.

(2) Yang Qiao Lu: The green is bright and sunny, like a column of green water, the color is fresh and tender, and it is very attractive. It is the top grade of jadeite.

(3) Light Sun Green: Slightly transparent to translucent, the green is light and bright, pure and beautiful to the eye. It is a mid-range jadeite.

(4) Light water green: The green is light and uniform, but not bright, and has good transparency. It is low-grade jadeite.

Experts often use the term "color strength" to describe the saturation of jadeite color. For example, a rich, full green jadeite ring face will not lose color no matter from what angle you look at it. This is called "full color strength" or "bright water". If the green is rich when displayed, but appears light when picked up, this is called "insufficient color strength"; there is also a type of jadeite that appears dark when displayed, but green when viewed through, which is called "covering water".

3. Classification by green shape and uniformity

(1) Full green: Full green color is uniform throughout the body.

(2) Misty green: Green with uneven shades, distributed in a misty manner.

(3) Plum Blossom Green: The green is uneven, shaped like a plum blossom and distributed in spots. It is also called “dot green” or “starry sky”.

(4) Ribbon green: also known as “ribbon green”. The green color is distributed in bands, and when gambling on stones, the protruding bands are particularly preferred.

(5) Golden Green: Good transparency, rich and bright green, distributed in parallel and discontinuous threads. The jade is warm, tender, and elegant. The ones with less internal flaws and cotton wax are high-grade varieties.

(6) Lumpy Green: Green appears in lumps of varying sizes that are unrelated to each other. When observing the color of jadeite, it is important to observe it under natural light and avoid direct light. Do not use general light or transmitted light to evaluate the color. Because it looks more beautiful when observed under light than under natural light. When observed under transmitted light, the green color is less uniform.

4. Jadeite of other colors

In addition to green, jade also has other colors, the most common ones are red, yellow, purple, white, etc.

(1) Red jadeite: commonly known as “jade color”. Red jadeite is mostly the surface part of the jade. Also known as "red skin" or "red fog", it is formed by the impregnation of hematite during secondary action. Natural red jadeite of good quality is rare. The best red color is called "Cockscomb Red". The red is bright and vivid, and the jade is delicate and transparent. It can be made into carvings or jade bracelets. High-end red jade carvings are also of extraordinary value. Sotheby's auction house once auctioned an excellent red jadeite carving for a whopping HK$3.8 million.

(2) Yellow jadeite: commonly known as "yellow jade". In the seed material, it is located above the red jadeite, closer to the surface, and is impregnated with limonite. Most yellow jades are turbid and often brown in color. They are not bright enough, nor transparent enough. Natural high-quality yellow jade is also called "golden jadeite". It is orange or honey-colored, crystal clear, and is the best grade of yellow jade. It is relatively rare. Often deep red or bright red jade is formed by heating yellow jade (oxidation of limonite to hematite). Yellow jade can be used to make colorful carvings, bracelets, and necklaces. Sometimes it coexists with emerald green or violet blue in a piece of jade, commonly known as "Fu Lu Shou" or "The Three Heroes of Peach Garden". It is made into carvings or bracelets and other ornaments, which are very attractive. If the "water" is good and the quality is good, the price will be extraordinary.

(3) Purple jadeite: commonly known as "green", also known as "violet blue". Depending on the different tones of purple, it is divided into pink purple, eggplant purple and blue purple. The color is lighter and mostly opaque, so it is generally not used for ring faces. It is often used for large carvings and small pendants. If both lavender and light green colors exist in the same piece of jade, it is called "spring color", which is a rare and good material for carving. The highly transparent violet-blue color is very rare and has a high value.

Jadeite color classification method:

The color of jade is mainly caused by the different coloring elements it contains. Its color has a great influence on the value of jade. The value of jade of different colors varies greatly. Therefore, it is necessary to scientifically classify the color of jade. At present, the color classification of jadeite in the market mainly uses physical standard samples to compare and grade the colors. There is no feasible scientific and systematic standard for how to clearly define the division of jadeite color varieties. The more commonly used method for jade color detection is direct visual observation by the colorist. Since visual color measurement will be affected by the lighting source, observation angle and the observer's own color discrimination ability, it can easily lead to deviations in color assessment results. Therefore, in order to improve the accuracy of jade color identification results, the color of jade can be classified and visually inspected in a standard light source box.

We all know that color is a subjective color sensation produced by people, and different observers have different abilities to perceive color. And the color discrimination ability of the same person's eyes will also change with age and health status. Therefore, one of the factors that affect color perception is the observer.

Secondly, different light sources have different spectral energy distribution and colors. Under their illumination, the color of the object's surface will also change accordingly. Therefore, different lighting sources will also affect people's evaluation of color. For objects that do not emit light themselves, the color they present is mainly the color sensation formed by the absorption, transmission, refraction and reflection of the light source, and a part of the light is received by the human eye. Due to the different light absorption characteristics of different objects, different colors will be presented under the same light source conditions.

To sum up, the factors that affect color perception are mainly the observer (human eye), the lighting source and the observed object itself. In addition, interference from the surrounding colors, observation angle, sample size, etc. can also cause people to have different color perceptions.

In colorimetry, in order to achieve the requirements of the standard illuminant specified by CIE and facilitate the transmission of color measurement results, the concept of standard light source was proposed to specifically realize the spectral power distribution required by the standard illuminant. The so-called standard light source refers to a light source that meets the color measurement requirements in colorimetry. Standard light boxes, as lighting box equipment for color detection, are mostly equipped with a variety of standard light sources that meet color detection requirements, such as D65, TL84, CWF, F/A, UV, etc. Users only need to put jade samples and test pieces or color matching cards into the standard light box and perform color matching according to the operating instructions to accurately evaluate the color of jade and thus accurately classify its color.

However, when using a standard light box to classify the color of jadeite, you also need to pay attention to the following matters:

1. Observation angle requirements

Scientific experiments have confirmed that different observation angles will directly affect the evaluation results. Therefore, according to international regulations, there are generally only two observation angles for standard light sources: zero-degree light source, 45-degree observation (0°-45°) and 45-degree light source, zero-degree observation (0°-45°).

2. Environmental requirements for color matching

When performing color detection, other lighting sources cannot directly or indirectly affect the surface of the observed object. Therefore, we require that the color correction light box usually uses a neutral gray inner wall with a reflectivity of less than 60%, and the observer's clothes must also be gray, and no other colors can be used. Moreover, when observing color transmission photographs, there must be a border with a width of more than 50 mm around the photo, and the border color must be greater than 90% black.

3. Sample placement requirements

Since most color-matching light boxes are relatively regular cubes (some light boxes have special box structures), the light source detection effect will be more uniform if it is located in the middle of the light box, and the influence of external light sources can be minimized. Therefore, when we visit the samples to be tested, we must try our best to align them in the center of the light box. If you are testing two or more items, it is best to place them side by side, close together, without separating them or overlapping them.

4. Metamerism detection

Only color matching light box products equipped with two or more light sources have this function. For example, when two samples are tested in a D65 light box, they are the same color; however, under light source A, the colors are different. This is the metamerism effect.

fcpf11