Color grading method for pink cultivated diamond

Abstract

The invention provides a color grading method for pink cultivated diamonds, which is characterized by comprising the following steps: S1, sequentially comparing pink cultivated diamonds to be detected with a plurality of hue physical standard samples, and obtaining the hue grade of the pink cultivated diamonds to be detected according to hue comparison; s2, sequentially comparing the pink cultivated diamond to be detected with a plurality of chroma physical standard samples, and obtaining the chroma level of the pink cultivated diamond to be detected according to saturation comparison and lightness comparison; and S3, classifying the colors of the pink cultivated diamond to be detected according to the tone level and the chroma level of the pink cultivated diamond to be detected. According to the method, the color grading interval can be refined, the color grading standard can be unified and perfected, and standardization and refinement of color grading of pink cultivated diamonds can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of diamond color grading, and more particularly to a color grading method for pink cultured diamonds. Background Art

[0002] Colored diamonds are rich in color and have gradually entered the mass consumption market in recent years. Natural colored diamonds have low reserves and are difficult to mine, with extremely low production and rising market prices year by year. Among colored diamonds, pink diamonds are favored by the gem market, but their low production and unattainable prices often discourage ordinary consumers. Lab-Grown Diamonds are artificially grown diamonds of gem quality, with almost the same physical, chemical properties and crystal structure as natural diamonds. Pink cultured diamonds have the advantage of being cheap, and the market demand for cultured diamonds in my country is still increasing.

[0003] At present, compared with colorless diamonds, yellow diamonds and other gemstones, the color grading of pink cultured diamonds is not standardized enough, lacking unified and clear grading standards and grading terms, which indirectly brings certain confusion to market transactions, disrupts the healthy and orderly development of the pink cultured diamond market to a great extent, and also brings many troubles to consumers. Therefore, it is very necessary and urgent to conduct systematic research on pink cultured diamonds, accurately evaluate the quality of pink cultured diamonds, and improve their grading standards. This is a prerequisite for ensuring that consumer interests are not infringed, improving the intensity and level of market supervision, ensuring the standardization and orderliness of the pink cultured diamond market, and achieving healthy market development. Summary of the invention

[0004] The present invention aims to provide a scientific, reasonable and operable method for grading the color of pink cultured diamonds. The color grading method is used in conjunction with a physical standard sample of pink cultured diamonds. The physical standard sample of pink cultured diamonds fills the gap between pink diamonds and pink cultured diamond colorimetric stones, is reproducible, and has great promotional significance.

[0005] In order to achieve the above object, the present invention provides a method for color grading of pink cultured diamonds, comprising the following steps: Step S1: comparing the pink cultured diamond to be tested with a number of physical standard samples of color tone in sequence, and obtaining the color tone level of the pink cultured diamond to be tested according to the color tone comparison; Step S2: comparing the pink cultured diamond to be tested with a number of physical standard samples of chroma in sequence, and obtaining the chroma level of the pink cultured diamond to be tested based on saturation comparison and brightness comparison; Step S3: classifying the color of the pink cultured diamond to be tested according to the hue level and chroma level to which the pink cultured diamond to be tested belongs.

[0006] Furthermore, the color tone levels include pink, slightly purple pink and slightly orange pink.

[0007] Furthermore, the step S1 specifically includes: Comparing the pink cultured diamond to be tested with a first color tone physical standard sample and / or a second color tone physical standard sample, wherein the color card code of the first color tone physical standard sample in the Munsell color card standard is 10RP 5 / 8, and the color card code of the second color tone physical standard sample in the Munsell color card standard is 5R 5 / 8; If the purple degree of the hue of the pink cultured diamond to be tested is lower than or equal to that of the first hue physical standard sample, and the orange degree of the hue of the pink cultured diamond to be tested is lower than or equal to that of the second hue physical standard sample, the hue level of the pink cultured diamond to be tested is determined to be pink; If the hue of the pink cultured diamond to be tested is more purple than that of the first hue physical standard sample, the hue level of the pink cultured diamond to be tested is determined to be slightly purple pink; If the hue of the pink cultured diamond to be tested is more orange-tinted than that of the second hue physical standard sample, the hue level of the pink cultured diamond to be tested is determined to be slightly orange-pink.

[0008] Furthermore, the chroma levels include: dark, vivid, deep, intense, colorful, light, and pale.

[0009] Furthermore, the step S2 specifically includes the following steps: Step S21: comparing the pink cultured diamond to be tested with a first chromaticity physical standard sample, and if the saturation of the pink cultured diamond to be tested is higher than or equal to the first chromaticity physical standard sample, determining that the chromaticity level of the pink cultured diamond to be tested is Fancy Vivid; If the saturation of the pink cultured diamond to be tested is lower than that of the first chroma physical standard sample, proceed to step S22; Step S22: comparing the pink cultured diamond to be tested with the third chromaticity physical standard sample. If the brightness of the pink cultured diamond to be tested is higher than or equal to the third chromaticity physical standard sample, proceed to step S24. If the brightness of the pink cultured diamond to be tested is lower than that of the third chroma physical standard sample, proceed to step S23; Step S23: comparing the pink cultured diamond to be tested with a second chroma physical standard sample, and if the saturation of the pink cultured diamond to be tested is higher than or equal to the second chroma physical standard sample, determining that the chroma level of the pink cultured diamond to be tested is deep color; If the saturation of the pink cultured diamond to be tested is lower than that of the second chroma physical standard sample, the chroma level of the pink cultured diamond to be tested is determined to be dark; Step S24: comparing the pink cultured diamond to be tested with the third chroma physical standard sample, and if the saturation of the pink cultured diamond to be tested is higher than or equal to the third chroma physical standard sample, determining that the chroma level of the pink cultured diamond to be tested is intense color; If the saturation of the pink cultured diamond to be tested is lower than that of the third chroma physical standard sample, proceed to step S25; Step S25: comparing the pink cultured diamond to be tested with a physical standard sample of the fourth chroma. If the brightness of the pink cultured diamond to be tested is higher than or equal to the physical standard sample of the fourth chroma, proceed to step S26; If the brightness of the pink cultured diamond to be tested is lower than that of the fourth chroma physical standard sample, the chroma level of the pink cultured diamond to be tested is determined to be colorful; Step S26: comparing the pink cultured diamond to be tested with the fourth chroma physical standard sample, if the saturation of the pink cultured diamond to be tested is higher than or equal to the fourth chroma physical standard sample, determining that the chroma level of the pink cultured diamond to be tested is colorful; If the saturation of the pink cultured diamond to be tested is lower than that of the fourth chroma physical standard sample, proceed to step S27; Step S27: comparing the pink cultured diamond to be tested with a fifth chroma physical standard sample, if the brightness of the pink cultured diamond to be tested is higher than that of the fifth chroma physical standard sample, determining that the chroma level of the pink cultured diamond to be tested is light; If the brightness of the pink cultured diamond to be tested is lower than or equal to the fifth chroma physical standard sample, the chroma level of the pink cultured diamond to be tested is determined to be light color.

[0010] Furthermore, the comparison of the pink cultured diamond to be tested with the physical standard sample of hue or the physical standard sample of chroma is carried out in an indoor environment without direct sunlight, and the hue of the indoor environment is white or gray.

[0011] Furthermore, when the pink cultured diamond to be tested is compared with the physical standard sample of hue or the physical standard sample of chroma, a fluorescent lamp with a color temperature of 6500K is used for illumination, and a color plate or color comparison paper is used as the background.

[0012] Furthermore, the cut shapes of the physical standard sample of hue and the physical standard sample of chroma are both cushion-shaped.

[0013] In summary, compared with the prior art, the present invention has the following beneficial effects: 1. The color determination method of the Munsell color system is adopted to define the color of pink cultured diamonds from three dimensions: hue, lightness and saturation. A total of 21 colors are divided, including 3 hue types and 7 saturation levels, which brings scientific, clear and accurate color definition.

[0014] 2. The structure of combining physical standard sample comparison with sensory evaluation method can improve the accuracy of visual results and reduce subjectivity and randomness.

[0015] 3. The simple and easy classification method is adopted, which brings practicality and operability, and is easy to promote and popularize in laboratory environments and among professional training personnel.

[0016] 4. The method of referring to the internationally accepted evaluation system is adopted to bring about international comparability and make the results internationally recognized.

[0017] 5. The adoption of a unified pink cultured diamond color grading standard brings about market standardization, reduces confusion in transactions and consumer confusion. The adoption of clear grading standards protects consumer interests, ensures that consumers can make purchasing decisions based on accurate information, promotes market development, and contributes to the healthy development of the market and the establishment of consumer confidence.

[0018] Therefore, the present invention can accurately evaluate the quality of pink cultured diamonds, improve the color grading standard of pink cultured diamonds, is beneficial to protecting the interests of consumers from infringement, and is beneficial to improving the intensity and level of market supervision, thereby ensuring that the pink cultured diamond market is standardized and orderly, and achieving the healthy development of the pink cultured diamond market. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A flow chart of a pink cultured diamond color grading method provided by the present invention; Figure 2 A logic block diagram of chroma level determination in a pink cultured diamond color grading method provided by the present invention; Figure 3 The chromaticity diagram to which the first to fifth chromaticity physical standard samples in the present invention belong; Figure 4 This is a physical picture of the first to fifth chromaticity physical standard samples in the present invention. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0021] The disclosure below provides different implementations or examples for implementing different structures of the present application. In order to simplify the disclosure of the present application, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present application. In addition, the present application may repeat reference numbers and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity, and does not itself indicate the relationship between the various implementations and / or settings discussed. The following is a detailed description of a color grading method for pink cultured diamonds provided by the present invention. It should be noted that the description order of the following embodiments is not intended to limit the preferred order of the embodiments.

[0022] Please see attached Figure 1 , a method for color grading of pink cultured diamonds, comprising the following steps: Step S1: comparing the pink cultured diamond to be tested with a number of physical standard samples of different hues in sequence, and obtaining the hue level of the pink cultured diamond to be tested according to the hue comparison; Step S2: comparing the pink cultured diamond to be tested with a number of physical standard samples of chroma in sequence, and obtaining the chroma level of the pink cultured diamond to be tested based on saturation comparison and brightness comparison; Step S3: Classify the color of the pink cultured diamond to be tested according to the hue level and saturation level of the pink cultured diamond to be tested.

[0023] In the prior art, the three attributes of color include hue, lightness, and saturation. Hue refers to the appearance of color, i.e. red, yellow, green, etc. Lightness refers to the brightness of color. In the Munsell color system, the absolute lightness of black is defined as 0 (ideal black), and the absolute lightness of white is defined as 100 (ideal white); saturation refers to the relative difference between color and non-color. It is a color perception attribute that describes the degree to which the color deviates from the neutral gray of the same lightness. It is a subjective psychological quantity. It is generally directly expressed by the subjective observation of the pure color component in the color. Such as 2, 4, 6, etc. in the Munsell system. If saturation is also expressed as a percentage, its meaning is "color content" or "gray content".

[0024] In this embodiment, four indicators, namely "hue", "saturation", "brightness" and "color", are used in color classification. Hue refers to the color type of an image, which is expressed as color in a color image.

[0025] Saturation refers to the purity or vividness of color. Colors with high saturation appear more vivid, while colors with low saturation appear dull. Saturation can adjust the vividness of a color by changing its purity.

[0026] Brightness refers to the degree of lightness or darkness of a color. Colors with high brightness appear brighter, and colors with low brightness appear darker. Brightness can express the intensity of a light source or the degree of lightness or darkness of an object by changing the brightness of the color.

[0027] Chroma is a combination of saturation and brightness, and is a color perception attribute that describes the degree to which a color deviates from the neutral gray of the same brightness. The higher the chroma, the higher the saturation, the brightness tends to the middle value, and the more vivid it feels; the lower the chroma, the lower the saturation, the brightness tends to the middle value, and the more turbid or dim it feels.

[0028] Specifically, the pink cultured diamond to be tested is compared with several physical standard samples of hue and several physical standard samples of chroma to obtain its hue level and chroma level, and then the color of the pink cultured diamond to be tested is comprehensively classified according to the obtained hue level and chroma level, which helps to improve the detail and accuracy of the color grading of pink cultured diamonds. By refining the color grading, it is helpful to more accurately describe the color characteristics of pink cultured diamonds.

[0029] This embodiment introduces and comprehensively considers the four indicators of "hue", "saturation", "brightness" and "chroma" when grading color, which can refine the grading intervals, unify and improve the grading standards, and is conducive to the standardization and refinement of the color grading of pink cultured diamonds.

[0030] In an optional embodiment, the color tone levels are divided into three types: pink, slightly purple pink, and slightly orange pink.

[0031] Correspondingly, in an optional implementation, the step of comparing and determining the hue level, i.e., step S1, specifically includes: Compare the pink cultured diamond to be tested with a physical standard sample of the first color tone and / or a physical standard sample of the second color tone, wherein the color card code of the physical standard sample of the first color tone in the Munsell color card standard is 10RP 5 / 8, and the color card code of the physical standard sample of the second color tone in the Munsell color card standard is 5R 5 / 8; If the purple hue of the pink cultured diamond to be tested is lower than or equal to the first hue physical standard sample, and the orange hue of the pink cultured diamond to be tested is lower than or equal to the second hue physical standard sample, then "pink" is used to represent the hue level of the pink cultured diamond to be tested; If the hue of the pink cultured diamond to be tested is more purple than that of the physical standard sample of the first hue, the hue level of the pink cultured diamond to be tested is indicated by "slightly purple pink"; If the hue of the pink cultured diamond to be tested is more orange than that of the physical standard sample of the second hue, "slightly orange pink" will be used to indicate the hue level of the pink cultured diamond to be tested.

[0032] Specifically, the color card number of the physical standard sample of the first hue is 10RP 5 / 8 in the Munsell Color Book - Full Gloss, where "RP" stands for Purplish Red and "10" represents a specific level or hue position in Purplish Red. In the Munsell color system, each hue is divided into 10 levels (1 to 10) to describe the gradual change of the color. Level 5 usually represents the middle color or typical color of the hue, while "10" may represent a darker or lighter variant of the hue. The first half "5" in "5 / 8" represents the lightness level. Lightness refers to the lightness or darkness of a color, which reflects the color's ability to reflect or absorb light. In the Munsell color system, lightness is divided into multiple levels to describe the brightness change of a color. The second half "8" in "5 / 8" represents the saturation level. Saturation refers to the brightness of a color, which reflects the amount of gray in the color. In the Munsell color system, saturation is also divided into multiple levels to describe the change in the brightness of a color.

[0033] In summary, the color code "10RP 5 / 8" in the Munsell color standard represents a color with a specific hue (a variation of purple-red), lightness level (level 5) and saturation level (level 8). This color may visually appear as a purple-red hue with moderate brightness and high vividness.

[0034] Similarly, the color card number of the second color tone physical standard sample is 5R5 / 8 of the Munsell Color Guide - Full Gloss, which represents a color with a specific red hue, medium lightness and high purity. This color may visually appear as an orange hue with medium to medium-high lightness and saturation.

[0035] In this embodiment, only two unused pink cultured diamonds are used as physical reference standard samples for color tone classification.

[0036] If the purple or orange hue of the pink cultured diamond to be tested is relatively low, that is, the purple hue is lower than or equal to the first hue physical standard sample, and the orange hue is lower than or equal to the second hue physical standard sample, then "pink" can be used to represent the hue level of the pink cultured diamond to be tested.

[0037] If the hue of the pink cultured diamond to be tested is more purple and higher than the first hue of the physical standard sample, "slightly purple pink" can be used to indicate the hue level of the pink cultured diamond to be tested.

[0038] If the hue of the pink cultured diamond to be tested is more orange and higher than the second hue of the physical standard sample, "slightly orange pink" can be used to indicate the hue level of the pink cultured diamond to be tested.

[0039] In an optional implementation, the chroma levels are divided into seven types: Fancy Dark, Fancy Vivid, Fancy Deep, Fancy Intense, Fancy, Fancy Light and Light.

[0040] Correspondingly, such as Figure 2 As shown, in an optional implementation, the step of comparing and determining the chroma level, i.e., step S2, specifically includes the following steps: Step S21: comparing the pink cultured diamond to be tested with the first chroma physical standard sample, if the saturation of the pink cultured diamond to be tested is higher than or equal to the first chroma physical standard sample, the chroma level of the pink cultured diamond to be tested is determined to be Fancy Vivid; If the saturation of the pink cultured diamond to be tested is lower than that of the first chroma physical standard sample, proceed to step S22; Step S22: comparing the pink cultured diamond to be tested with the third chroma physical standard sample. If the brightness of the pink cultured diamond to be tested is higher than or equal to the third chroma physical standard sample, proceed to step S24. If the brightness of the pink cultured diamond to be tested is lower than the third chroma physical standard sample, proceed to step S23; Step S23: comparing the pink cultured diamond to be tested with the second chroma physical standard sample, if the saturation of the pink cultured diamond to be tested is higher than or equal to the second chroma physical standard sample, the chroma level of the pink cultured diamond to be tested is determined to be deep color; If the saturation of the pink cultured diamond to be tested is lower than that of the second chroma physical standard sample, the chroma level of the pink cultured diamond to be tested is determined to be dark; Step S24: comparing the pink cultured diamond to be tested with the third chroma physical standard sample, if the saturation of the pink cultured diamond to be tested is higher than or equal to the third chroma physical standard sample, the chroma level of the pink cultured diamond to be tested is determined to be intense color; If the saturation of the pink cultured diamond to be tested is lower than that of the third chroma physical standard sample, proceed to step S25; Step S25: comparing the pink cultured diamond to be tested with the physical standard sample of the fourth chroma. If the brightness of the pink cultured diamond to be tested is higher than or equal to the physical standard sample of the fourth chroma, proceed to step S26; If the brightness of the pink cultured diamond to be tested is lower than that of the fourth chroma physical standard sample, the chroma level of the pink cultured diamond to be tested is determined to be colorful; Step S26: comparing the pink cultured diamond to be tested with the fourth chroma physical standard sample, if the saturation of the pink cultured diamond to be tested is higher than or equal to the fourth chroma physical standard sample, the chroma level of the pink cultured diamond to be tested is determined to be colorful; If the saturation of the pink cultured diamond to be tested is lower than that of the fourth chroma physical standard sample, proceed to step S27; Step S27: comparing the pink cultured diamond to be tested with the fifth chroma physical standard sample. If the brightness of the pink cultured diamond to be tested is higher than the fifth chroma physical standard sample, the chroma level of the pink cultured diamond to be tested is determined to be light. If the brightness of the pink cultured diamond to be tested is lower than or equal to the fifth chroma physical standard sample, the chroma level of the pink cultured diamond to be tested is determined to be light color.

[0041] Specifically, Figure 3 As shown in the figure, the numbers 1 to 5 represent the chroma of the first to fifth chroma physical standard samples respectively. Figure 4 As shown, the numbers 1 to 5 in the figure represent the first to fifth chromaticity physical standard samples respectively.

[0042] In this embodiment, the chroma classification is based on the chroma classification of GIA natural colored diamonds. This classification is widely recognized and learnable, and has a long market promotion time and good results. In addition, the chroma classification reduces the 9 chroma levels of the GIA colored diamond color grading standard by two levels, Faint and Very light. These two levels rarely appear in pink cultured diamonds and have little significance for use. The two levels of Fancy Dark and Light are used as end member levels to control the quality of the chroma level of pink cultured diamonds and ensure the scientific nature of the sample color distribution.

[0043] This example determines the chroma level of pink cultured diamond samples by combining saturation and brightness, and uses 5 pink cultured diamonds of different chromas as physical reference standard samples for grading, so that the chroma level of pink cultured diamond samples can be determined simply and effectively through colorimetry.

[0044] In summary, the present invention adopts the color determination method of the Munsell color system to define the color of pink cultured diamonds from three dimensions: hue, lightness and saturation. A total of 21 colors are divided, including 3 hue types and 7 chroma levels, which brings scientificity, clarity and accuracy to the color definition. For example, if the hue level of a pink cultured diamond is "pink" and the chroma level is "dark color", the color of this pink cultured diamond is determined to be "dark color pink".

[0045] At the same time, the present invention improves the accuracy of visual results and reduces subjectivity and contingency by adopting a structure that combines physical standard sample comparison with sensory evaluation method. And by adopting a simple and easy grading method, it brings practicality and operability, which is convenient for promotion and popularization in laboratory environments and professional training personnel. By adopting a method that refers to the international general evaluation system, it brings international comparability, so that the results have international recognition. In addition, by adopting a unified pink cultured diamond color grading standard, the market is standardized, and the confusion in transactions and consumer confusion are reduced. The use of clear grading standards protects the interests of consumers, ensures that consumers can make purchasing decisions based on accurate information, promotes market development, and contributes to the healthy development of the market and the establishment of consumer confidence.

[0046] In an optional implementation, the comparison of the pink cultured diamond to be tested with a physical standard sample of hue or a physical standard sample of chroma is performed in an indoor environment without direct sunlight, and the hue of the indoor environment is white or gray.

[0047] Specifically, the current color grading standards are mainly based on the natural light performance of diamonds, but the color of diamonds may change under different light sources. Therefore, considering the different situations under different light sources, by ensuring that the color comparison is performed in an indoor environment without direct sunlight and the ambient color is white or gray, the influence of different light sources can be eliminated, thereby ensuring the accuracy of color grading.

[0048] In an optional implementation, when comparing the pink cultured diamond to be tested with a physical standard sample of hue or a physical standard sample of chroma, a fluorescent lamp with a color temperature of 6500K is used for illumination, and a color plate or color comparison paper is used as the background.

[0049] Specifically, the color temperature of 6500K is closer to the average natural light illumination effect in the northern region. It is recognized as a daylight source by international standards and is widely used in many fields, including color evaluation and printing. By using fluorescent lamps with a color temperature of 6500K for irradiation and using color plates or colorimetric paper as the background, the colorimetric method can be made more professional and scientific.

[0050] In an optional embodiment, if Figure 4 As shown, the cut shapes of the physical standard samples of hue and chroma are both cushion-shaped and similar cut shapes.

[0051] Specifically, in existing large colored diamonds, cushion-shaped is the mainstream cutting shape; and the cushion-shaped has high symmetry, good color enrichment, good curvature, no sharp edges, and high safety during use. By determining the cut shape of the hue physical standard sample and the chroma physical standard sample to be cushion-shaped or a similar cut facet, the standard sample can be easy to use and observe, which is conducive to improving the scientificity and convenience of the grading method provided by the present invention.

[0052] In summary, the color grading method for pink cultured diamonds provided by the present invention fully considers the actual conditions of different observers, the test environment, sample conditions and other factors, and comprehensively considers factors such as the behavior habits of the test personnel to obtain reasonable test conditions and operating procedures. In addition, academic research, market status, and the usage habits of merchants and consumers are also comprehensively considered to ensure that the invention is reasonable and practical, meets the actual needs of trade, quality inspection and other work, and also meets the actual needs of academic research and testing work.

[0053] In addition, the present invention fully considers factors such as the behavioral habits of testers, ensuring that the grading work can be completed under normal laboratory testing conditions and when the testers are well professionally trained. At the same time, it is easy to operate and is very suitable for the promotion and popularization of pink cultured diamond color grading.

[0054] The above is a detailed introduction to a color grading method for pink cultured diamonds provided in an embodiment of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present application. Ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for color grading of pink cultured diamonds, characterized in that: The following steps are involved: Step S1: comparing the pink cultured diamond to be tested with a number of physical standard samples of color tone in sequence, and obtaining the color tone level of the pink cultured diamond to be tested according to the color tone comparison; Step S2: comparing the pink cultured diamond to be tested with a number of physical standard samples of chroma in sequence, and obtaining the chroma level of the pink cultured diamond to be tested based on saturation comparison and brightness comparison; Step S3: classifying the color of the pink cultured diamond to be tested according to the hue level and chroma level to which the pink cultured diamond to be tested belongs.

2. The method for color grading of pink cultured diamonds according to claim 1, characterized in that: The shade levels include pink, slightly purple pink and slightly orange pink.

3. The method for color grading of pink cultured diamonds according to claim 2, characterized in that: The step S1 specifically includes: Comparing the pink cultured diamond to be tested with a first color tone physical standard sample and / or a second color tone physical standard sample, wherein the color card code of the first color tone physical standard sample in the Munsell color card standard is 10RP 5 / 8, and the color card code of the second color tone physical standard sample in the Munsell color card standard is 5R 5 / 8; If the purple degree of the hue of the pink cultured diamond to be tested is lower than or equal to that of the first hue physical standard sample, and the orange degree of the hue of the pink cultured diamond to be tested is lower than or equal to that of the second hue physical standard sample, the hue level of the pink cultured diamond to be tested is determined to be pink; If the hue of the pink cultured diamond to be tested is more purple than that of the first hue physical standard sample, the hue level of the pink cultured diamond to be tested is determined to be slightly purple pink; If the hue of the pink cultured diamond to be tested is more orange than that of the second hue physical standard sample, the hue level of the pink cultured diamond to be tested is determined to be slightly orange pink.

4. The method for color grading of pink cultured diamonds according to claim 1, characterized in that: The chroma levels include: dark, vivid, deep, intense, vivid, light and pale.

5. The method for color grading of pink cultured diamonds according to claim 4, characterized in that: The step S2 specifically includes the following steps: Step S21: comparing the pink cultured diamond to be tested with a first chromaticity physical standard sample, and if the saturation of the pink cultured diamond to be tested is higher than or equal to the first chromaticity physical standard sample, determining that the chromaticity level of the pink cultured diamond to be tested is Fancy Vivid; If the saturation of the pink cultured diamond to be tested is lower than that of the first chroma physical standard sample, proceed to step S22; Step S22: comparing the pink cultured diamond to be tested with the third chromaticity physical standard sample. If the brightness of the pink cultured diamond to be tested is higher than or equal to the third chromaticity physical standard sample, proceed to step S24. If the brightness of the pink cultured diamond to be tested is lower than that of the third chroma physical standard sample, proceed to step S23; Step S23: comparing the pink cultured diamond to be tested with a second chroma physical standard sample, and if the saturation of the pink cultured diamond to be tested is higher than or equal to the second chroma physical standard sample, determining that the chroma level of the pink cultured diamond to be tested is deep color; If the saturation of the pink cultured diamond to be tested is lower than that of the second chroma physical standard sample, the chroma level of the pink cultured diamond to be tested is determined to be dark; Step S24: comparing the pink cultured diamond to be tested with the third chroma physical standard sample, and if the saturation of the pink cultured diamond to be tested is higher than or equal to the third chroma physical standard sample, determining that the chroma level of the pink cultured diamond to be tested is intense color; If the saturation of the pink cultured diamond to be tested is lower than that of the third chroma physical standard sample, proceed to step S25; Step S25: comparing the pink cultured diamond to be tested with a physical standard sample of the fourth chroma. If the brightness of the pink cultured diamond to be tested is higher than or equal to the physical standard sample of the fourth chroma, proceed to step S26; If the brightness of the pink cultured diamond to be tested is lower than that of the fourth chroma physical standard sample, the chroma level of the pink cultured diamond to be tested is determined to be colorful; Step S26: comparing the pink cultured diamond to be tested with the fourth chroma physical standard sample, if the saturation of the pink cultured diamond to be tested is higher than or equal to the fourth chroma physical standard sample, determining that the chroma level of the pink cultured diamond to be tested is colorful; If the saturation of the pink cultured diamond to be tested is lower than that of the fourth chroma physical standard sample, proceed to step S27; Step S27: comparing the pink cultured diamond to be tested with a fifth chroma physical standard sample, if the brightness of the pink cultured diamond to be tested is higher than that of the fifth chroma physical standard sample, determining that the chroma level of the pink cultured diamond to be tested is light; If the brightness of the pink cultured diamond to be tested is lower than or equal to the fifth chroma physical standard sample, the chroma level of the pink cultured diamond to be tested is determined to be light color.

6. The method for color grading of pink cultured diamonds according to claim 1, characterized in that: The comparison of the pink cultured diamond to be tested with the physical standard sample of hue or the physical standard sample of chroma is carried out in an indoor environment without direct sunlight, and the hue of the indoor environment is white or gray.

7. The method for color grading of pink cultured diamonds according to claim 1, characterized in that: When comparing the pink cultured diamond to be tested with the physical standard sample of hue or the physical standard sample of chroma, a fluorescent lamp with a color temperature of 6500K is used for illumination, and a color plate or color comparison paper is used as the background.

8. The method for color grading of pink cultured diamonds according to claim 1, characterized in that: The cut shapes of the hue physical standard sample and the chroma physical standard sample are both cushion-shaped.

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