Color grading method for sea sapphire

Abstract

The invention relates to a color grading method for sea sapphire, and belongs to the technical field of gem detection. The method comprises the following steps: dividing color category classification standards of sea sapphire according to colorimetric parameters such as lightness V, saturation S and hue angle H; measuring colorimetric parameters such as lightness V, saturation S and hue angle H of the to-be-classified sea sapphire through a colorimeter; and judging the color level of the to-be-classified sea sapphire according to the colorimetric parameters of the brightness V, the saturation S and the hue angle H of the to-be-classified sea sapphire. According to the method, H, S and V are used for carrying out color category classification on the sea sapphire, and the problem that no uniform standard for quantification exists when color division is carried out on the sea sapphire by naked eyes is solved.

Description

Technical Field

[0001] The invention relates to a method for grading the color of an aquamarine, and belongs to the technical field of gemstone detection. Background Art

[0002] Aquamarine is one of the rare gemstones, and its color is the main factor affecting its quality grade. At present, the color of aquamarine is judged only by naked eye observation, but naked eye observation is highly subjective. Different appraisers have different perceptions of color, and different observation angles will also affect their judgment. The jewelry appraisal industry does not have any numerical standards to quantify the color series of aquamarine, and it is impossible to scientifically and accurately derive the color series of aquamarine. Summary of the invention

[0003] Aiming at the problem that the existing naked eye identification is used to classify the color of aquamarine, but the classification cannot be done accurately, the present invention proposes a color grading method for aquamarine, which uses H, S and V to classify the color of aquamarine, and solves the problem that the color of aquamarine is divided by the naked eye without a unified standard for quantification.

[0004] The HSV color space is used, H (Hue) is the hue parameter, with a value range of 0°~360°, red is 0°, and starting from the counterclockwise direction, green is 120° and blue is 240°; the complementary colors are: yellow is 60°, cyan is 180°, and purple is 300°; S (Saturation) is the saturation, with a value range of 0~100%. The higher the saturation, the darker the color, and the lower the saturation, the lighter the color; V (Value) is the color value, with a value range of 0~100%. The higher the value, the brighter the color, and a value of 0 means pure black. This color space expresses the hue, vividness, and brightness of the color very intuitively, making it easy to compare colors.

[0005] A method for grading the color of an aquamarine, the specific steps are as follows: (1) The color classification standard of aquamarine is divided according to the colorimetric parameters of lightness V, saturation S and hue angle H; (2) Determine the colorimetric parameters of the aquamarine to be classified, namely, lightness V, saturation S and hue angle H, by using a colorimeter; (3) Determine the color grade of the aquamarine to be classified based on its colorimetric parameters of lightness V, saturation S and hue angle H.

[0006] The color classification standards of aquamarine are: If the saturation S≤15.00 and the hue angle 140.00≤H<170.00, the aquamarine is classified as green-blue series; If the saturation is 15.00<S≤25.00 and the hue angle is 170.00≤H<200.00, then the aquamarine is classified as sky blue series; If the saturation is 25.00<S≤35.00 and the hue angle is 200.00≤H<230.00, then the aquamarine is classified as a sea blue series; If the saturation S>35.00 and the hue angle 230.00≤H, the aquamarine is classified as azure series.

[0007] Preferably, the green-blue series subdivision standards are divided into: If the lightness V is less than 85.00, the aquamarine is classified as a dark green-blue series; If the brightness V>85.00, the aquamarine is classified as a bright green-blue series.

[0008] Preferably, the sky blue series subdivision standards are divided into: If the lightness V is less than 85.00, the aquamarine is classified as a dark sky blue series; If the brightness V>85.00, the aquamarine is classified as a bright sky blue series.

[0009] Preferably, the sea blue series subdivision standards are divided into: If the lightness V is less than 85.00, the aquamarine is classified as a dark sea blue series; If the brightness V>85.00, the aquamarine is classified as a bright sea blue series.

[0010] Preferably, the subdivision standards of the azure series are divided into: If the lightness V is less than 85.00, the aquamarine is classified as a dark blue series; If the brightness V>85.00, the aquamarine is classified as a bright blue series.

[0011] Preferably, the wavelength range of the colorimeter for colorimetry testing is visible light 380~700nm, the experimental lighting adopts the D65 light source in the CIE standard version lighting body, the wavelength interval is 10nm, the observer field of view is 10°, the collection integration time is 1600μs, and the environmental test is under natural light.

[0012] The beneficial effects of the present invention are: The invention divides the color classification standard of aquamarine by colorimetric parameters of lightness V, saturation S and hue angle H, uses a colorimeter to test the colorimetric parameters of aquamarine, and then divides the color classification standard of aquamarine according to the colorimetric parameters of lightness V, saturation S and hue angle H, so as to quantitatively grade the color of aquamarine, thereby solving the problem that the color of aquamarine is divided by naked eyes and there is no unified standard for quantification. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 These are actual pictures of the aquamarines of Examples 1 to 8. DETAILED DESCRIPTION

[0014] The present invention is further described in detail below in conjunction with specific implementation modes, but the protection scope of the present invention is not limited to the described contents. SUMMARY OF THE INVENTION A method for grading the color of an aquamarine, the specific steps are as follows: (1) The color classification standard of aquamarine is divided according to the colorimetric parameters of lightness V, saturation S and hue angle H; the color classification standard of aquamarine is: If the saturation S≤15.00 and the hue angle 140.00≤H<170.00, the aquamarine is classified as the green-blue series; specifically, the subdivision standards of the green-blue series are divided into: If the lightness V is less than 85.00, the aquamarine is classified as a dark green-blue series; If the brightness V>85.00, the aquamarine is classified as a bright green-blue series; If the saturation is 15.00<S≤25.00 and the hue angle is 170.00≤H<200.00, then aquamarine is classified as a sky blue series; specifically, the sky blue series subdivision standards are divided into: If the lightness V is less than 85.00, the aquamarine is classified as a dark sky blue series; If the lightness V>85.00, the aquamarine is classified as bright sky blue series; If the saturation is 25.00<S≤35.00 and the hue angle is 200.00≤H<230.00, then aquamarine is classified as aquamarine series; specifically, the aquamarine series subdivision standards are divided into: If the lightness V is less than 85.00, the aquamarine is classified as a dark sea blue series; If the brightness V>85.00, the aquamarine is classified as a bright sea blue series; If the saturation S>35.00 and the hue angle 230.00≤H, the aquamarine is classified as the azure series; specifically, the azure series subdivision standards are divided into: If the lightness V is less than 85.00, the aquamarine is classified as a dark blue series; If the brightness V>85.00, the aquamarine is classified as a bright blue series; (2) Determine the chromaticity parameters of the aquamarine to be classified, namely, lightness V, saturation S and hue angle H, by using a colorimeter; the wavelength range of the colorimeter for chromaticity testing is visible light 380-700 nm, the experimental illumination adopts the D65 light source in the CIE standard version illumination body, the wavelength interval is 10 nm, the observer's field of view is 10°, the collection integration time is 1600 μs, and the environmental test is under natural light; (3) Determine the color grade of the aquamarine to be classified based on its colorimetric parameters of lightness V, saturation S and hue angle H.

[0016] Example 1: Aquamarine (see Figure 1 The color grading method in a) is as follows: (1) The color classification standard of aquamarine is divided according to the colorimetric parameters of lightness V, saturation S and hue angle H; the color classification standard of aquamarine is: If the saturation S≤15.00 and the hue angle 140.00≤H<170.00, the aquamarine is classified as the green-blue series; specifically, the subdivision standards of the green-blue series are divided into: If the lightness V is less than 85.00, the aquamarine is classified as a dark green-blue series; If the brightness V>85.00, the aquamarine is classified as a bright green-blue series; If the saturation is 15.00<S≤25.00 and the hue angle is 170.00≤H<200.00, then aquamarine is classified as a sky blue series; specifically, the sky blue series subdivision standards are divided into: If the lightness V is less than 85.00, the aquamarine is classified as a dark sky blue series; If the lightness V>85.00, the aquamarine is classified as bright sky blue series; If the saturation is 25.00<S≤35.00 and the hue angle is 200.00≤H<230.00, then aquamarine is classified as aquamarine series; specifically, the aquamarine series subdivision standards are divided into: If the lightness V is less than 85.00, the aquamarine is classified as a dark sea blue series; If the brightness V>85.00, the aquamarine is classified as a bright sea blue series; If the saturation S>35.00 and the hue angle 230.00≤H, the aquamarine is classified as the azure series; specifically, the azure series subdivision standards are divided into: If the lightness V is less than 85.00, the aquamarine is classified as a dark blue series; If the brightness V>85.00, the aquamarine is classified as a bright blue series; (2) Determine the colorimetric parameters of the aquamarine to be classified, namely, lightness V, saturation S and hue angle H, by using a colorimeter; the wavelength range of the colorimeter for colorimetric testing is visible light 380-700 nm, the experimental lighting adopts the D65 light source in the CIE standard version lighting body, the wavelength interval is 10 nm, the observer's field of view is 10°, the collection integration time is 1600 μs, and the environmental test is under natural light; the hue angle H of the aquamarine in this example is 161.48, the saturation S is 9.31, and the lightness V is 100.00; (3) Determine the color grade of the aquamarine to be classified based on the colorimetric parameters of the aquamarine to be classified, namely, lightness V, saturation S and hue angle H; Since the saturation S is 9.31≤15.00, 140.00<hue angle H is 161.48≤170.00; therefore, the aquamarine sample in this embodiment is classified into the green-blue series; specifically, the lightness V is 100.00>85.00, and the aquamarine is classified into the bright green-blue series.

[0017] Example 2: Aquamarine (see Figure 1 The color grading method in b) is as follows: (1) A color classification standard for aquamarine is divided according to the colorimetric parameters of lightness V, saturation S and hue angle H; the color classification standard for aquamarine is shown in Example 1; (2) Determine the colorimetric parameters of the aquamarine to be classified, namely, lightness V, saturation S and hue angle H, by using a colorimeter; the wavelength range of the colorimeter for colorimetric testing is visible light 380-700 nm, the experimental lighting adopts the D65 light source in the CIE standard version lighting body, the wavelength interval is 10 nm, the observer's field of view is 10°, the collection integration time is 1600 μs, and the environmental test is under natural light; the hue angle H of the aquamarine in this example is 156.37, the saturation S is 9.29, and the lightness V is 99.67; (3) Determine the color grade of the aquamarine to be classified based on the colorimetric parameters of the aquamarine to be classified, namely, lightness V, saturation S and hue angle H; Since the saturation S is 9.29≤15.00, 140.00<hue angle H is 156.37≤170.00; therefore, the aquamarine sample in this embodiment is classified into the green-blue series; specifically, the lightness V is 99.67>85.00, and the aquamarine is classified into the bright green-blue series.

[0018] Example 3: Aquamarine (see Figure 1 The color grading method in (c) is as follows: (1) A color classification standard for aquamarine is divided according to the colorimetric parameters of lightness V, saturation S and hue angle H; the color classification standard for aquamarine is shown in Example 1; (2) Determine the colorimetric parameters of the aquamarine to be classified, namely, lightness V, saturation S and hue angle H, by using a colorimeter; the wavelength range of the colorimeter for colorimetric testing is visible light 380-700 nm, the experimental lighting adopts the D65 light source in the CIE standard version lighting body, the wavelength interval is 10 nm, the observer's field of view is 10°, the collection integration time is 1600 μs, and the environmental test is under natural light; the hue angle H of the aquamarine in this example is 180.00, the saturation S is 19.55, and the lightness V is 100.00; (3) Determine the color grade of the aquamarine to be classified based on the colorimetric parameters of the aquamarine to be classified, namely, lightness V, saturation S and hue angle H; Since 15.00<saturation S is 19.55≤25.00, 170.00≤hue angle H is 180.00<200.00; therefore, the aquamarine sample in this embodiment is classified into the sky blue series; specifically, the lightness V is 100>85.00, then the aquamarine is classified into the bright sky blue series.

[0019] Example 4: Aquamarine (see Figure 1 The color grading method in (d) is as follows: (1) A color classification standard for aquamarine is divided according to the colorimetric parameters of lightness V, saturation S and hue angle H; the color classification standard for aquamarine is shown in Example 1; (2) Determine the colorimetric parameters of the aquamarine to be classified, namely, lightness V, saturation S and hue angle H, by using a colorimeter; the wavelength range of the colorimeter for colorimetric testing is visible light 380-700 nm, the experimental lighting adopts the D65 light source in the CIE standard version lighting body, the wavelength interval is 10 nm, the observer's field of view is 10°, the collection integration time is 1600 μs, and the environmental test is under natural light; the hue angle H of the aquamarine in this example is 194.87, the saturation S is 16.25, and the lightness V is 98.71; (3) Determine the color grade of the aquamarine to be classified based on the colorimetric parameters of the aquamarine to be classified, namely, lightness V, saturation S and hue angle H; Since 15.00<saturation S is 16.25≤25.00, 170.00≤hue angle H is 194.87<200.00; therefore, the aquamarine sample in this embodiment is classified as a sky blue series; specifically, the lightness V is 98.71>85.00, and the aquamarine is classified as a bright sky blue series.

[0020] Example 5: Aquamarine (see Figure 1 The color grading method in (e) is as follows: (1) A color classification standard for aquamarine is divided according to the colorimetric parameters of lightness V, saturation S and hue angle H; the color classification standard for aquamarine is shown in Example 1; (2) Determine the colorimetric parameters of the aquamarine to be classified, namely, lightness V, saturation S and hue angle H, by using a colorimeter; the wavelength range of the colorimeter for colorimetric testing is visible light 380-700 nm, the experimental lighting adopts the D65 light source in the CIE standard version lighting body, the wavelength interval is 10 nm, the observer's field of view is 10°, the collection integration time is 1600 μs, and the environmental test is under natural light; the hue angle H of the aquamarine in this example is 196.21, the saturation S is 18.26, and the lightness V is 97.65; (3) Determine the color grade of the aquamarine to be classified based on the colorimetric parameters of the aquamarine to be classified, namely, lightness V, saturation S and hue angle H; Since 15.00<saturation S is 18.26≤25.00, 170.00≤hue angle H is 196.21<200.00; therefore, the aquamarine sample in this embodiment is classified as a sky blue series; specifically, the lightness V is 97.65>85.00, and the aquamarine is classified as a bright sky blue series.

[0021] Example 6: Aquamarine (see Figure 1 The color grading method in (f) is as follows: (1) A color classification standard for aquamarine is divided according to the colorimetric parameters of lightness V, saturation S and hue angle H; the color classification standard for aquamarine is shown in Example 1; (2) Determine the colorimetric parameters of the aquamarine to be classified, namely, lightness V, saturation S and hue angle H, by using a colorimeter; the wavelength range of the colorimeter for colorimetric testing is visible light 380-700 nm, the experimental lighting adopts the D65 light source in the CIE standard version lighting body, the wavelength interval is 10 nm, the observer's field of view is 10°, the collection integration time is 1600 μs, and the environmental test is under natural light; the hue angle H of the aquamarine in this example is 204.09, the saturation S is 25.70, and the lightness V is 100.00; (3) Determine the color grade of the aquamarine to be classified based on the colorimetric parameters of the aquamarine to be classified, namely, lightness V, saturation S and hue angle H; Since 25.00<saturation S is 25.70≤35.00, 200.00≤hue angle H is 204.09<230.00; therefore, the aquamarine sample in this embodiment is classified into the sea blue series; specifically, the lightness V is 100>85.00, and the aquamarine is classified into the bright sea blue series.

[0022] Example 7: Aquamarine (see Figure 1The color grading method in g) has the following specific steps: (1) A color classification standard for aquamarine is divided according to the colorimetric parameters of lightness V, saturation S and hue angle H; the color classification standard for aquamarine is shown in Example 1; (2) Determine the colorimetric parameters of the aquamarine to be classified, namely, lightness V, saturation S and hue angle H, by using a colorimeter; the wavelength range of the colorimeter for colorimetric testing is visible light 380-700 nm, the experimental lighting adopts the D65 light source in the CIE standard version lighting body, the wavelength interval is 10 nm, the observer's field of view is 10°, the collection integration time is 1600 μs, and the environmental test is under natural light; the hue angle H of the aquamarine in this example is 210.77, the saturation S is 35.94, and the lightness V is 98.88; (3) Determine the color grade of the aquamarine to be classified based on the colorimetric parameters of the aquamarine to be classified, namely, lightness V, saturation S and hue angle H; Since 25.00<saturation S is 34.94≤35.00, 200.00≤hue angle H is 210.77<230.00; therefore, the aquamarine sample in this embodiment is classified into the sea blue series; specifically, the lightness V is 98.88>85.00, and the aquamarine is classified into the bright sea blue series.

[0023] Example 8: Aquamarine (see Figure 1 The color grading method in h) is as follows: (1) A color classification standard for aquamarine is divided according to the colorimetric parameters of lightness V, saturation S and hue angle H; the color classification standard for aquamarine is shown in Example 1; (2) Determine the colorimetric parameters of the aquamarine to be classified, namely, lightness V, saturation S and hue angle H, by using a colorimeter; the wavelength range of the colorimeter for colorimetric testing is visible light 380-700 nm, the experimental lighting adopts the D65 light source in the CIE standard version lighting body, the wavelength interval is 10 nm, the observer's field of view is 10°, the collection integration time is 1600 μs, and the environmental test is under natural light; the hue angle H of the aquamarine in this example is 209.34, the saturation S is 30.20, and the lightness V is 94.47; (3) Determine the color grade of the aquamarine to be classified based on the colorimetric parameters of the aquamarine to be classified, namely, lightness V, saturation S and hue angle H; Since 25.00<saturation S is 30.20≤35.00, 200.00≤hue angle H is 209.34<230.00; therefore, the aquamarine sample in this embodiment is classified into the sea blue series; specifically, the lightness V is 94.47>85.00, and the aquamarine is classified into the bright sea blue series.

[0024] The specific implementation modes of the present invention are described in detail above, but the present invention is not limited to the above implementation modes, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A method for grading the color of aquamarine, characterized in that: The specific steps are as follows: (1) The color classification standard of aquamarine is divided according to the colorimetric parameters of lightness V, saturation S and hue angle H; (2) Determine the colorimetric parameters of the aquamarine to be classified, namely, lightness V, saturation S and hue angle H, by using a colorimeter; (3) Determine the color grade of the aquamarine to be classified based on its colorimetric parameters of lightness V, saturation S and hue angle H.

2. The method for grading the color of aquamarine according to claim 1, characterized in that: The color classification standards for aquamarine are: If the saturation S≤15.00 and the hue angle 140.00≤H<170.00, the aquamarine is classified as green-blue series; If the saturation is 15.00<S≤25.00 and the hue angle is 170.00≤H<200.00, then the aquamarine is classified as sky blue series; If the saturation is 25.00<S≤35.00 and the hue angle is 200.00≤H<230.00, then the aquamarine is classified as a sea blue series; If the saturation S>35.00 and the hue angle 230.00≤H, the aquamarine is classified as azure series.

3. The method for grading the color of aquamarine according to claim 2, characterized in that: The green-blue series is divided into the following categories: If the lightness V is less than 85.00, the aquamarine is classified as a dark green-blue series; If the brightness V>85.00, the aquamarine is classified as a bright green-blue series.

4. The method for grading the color of aquamarine according to claim 2, characterized in that: The sky blue series is divided into the following categories: If the lightness V is less than 85.00, the aquamarine is classified as a dark sky blue series; If the brightness V>85.00, the aquamarine is classified as a bright sky blue series.

5. The method for grading the color of aquamarine according to claim 2, characterized in that: The sea blue series is divided into the following categories: If the lightness V is less than 85.00, the aquamarine is classified as a dark sea blue series; If the brightness V>85.00, the aquamarine is classified as a bright sea blue series.

6. The method for grading the color of aquamarine according to claim 2, characterized in that: The subdivision standards of the azure series are divided into: If the lightness V is less than 85.00, the aquamarine is classified as a dark blue series; If the brightness V>85.00, the aquamarine is classified as a bright blue series.

Images