JP4663855B2 - How to identify decorative gems - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for identifying a new diamond cut for ornamental jewelry, in particular for ornamental purposes.
[0002]
[Prior art]
The decorative gem is cut. The diamond 80 is brilliantly cut and has a shape as shown in FIG. 10A is a plan view, FIG. 10B is a side view, and FIG. 10C is a bottom view. Here, the upper surface is a table surface 81, and the upper part from the girdle 82 is a crown portion having a substantially truncated cone shape, and the table surface forms the top surface of the truncated cone. The lower part of the girdle 82 is a substantially conical pavilion part, and there is a part called a curette 83 at the apex thereof. There are usually eight main facets 84 on the outer periphery of the crown, a star facet 85 is formed between the table outer periphery and the main facet, and an upper girdle facet 86 is provided between the girdle 82 and the main facet 84. Is formed. In addition, eight main facets 87 are normally formed on the outer periphery of the pavilion portion, and a lower girdle facet 88 is formed between the girdle and the main facet.
[0003]
4C used for diamond evaluation is carat (weight), color, clarity, and cut. Of these, carat, color, and clarity are properties that the stone originally has, and human hands Although it cannot be added, the brightness can be changed by the way of cutting. For this purpose, various cuts have been studied and applied to jewelry.
[0004]
The decorative gem is cut and attached to the pedestal. For example, as shown in FIG. 11, the diamond 80 has a pavilion portion embedded in a pedestal 90, and a crown portion above the girdle 82 and a table 81 protrude from the pedestal 90. For this reason, the table and crown are visible from the outside, but the pavilion is invisible from the outside of the pedestal 90, and the pavilion is cut from above through the table and crown. It is only observed.
[0005]
The diamond seen from the table is shining and observed because the light incident from each surface of the table and crown is refracted and reflected inside the diamond, and the light coming out of the diamond crown and table reaches the observer. Because.
[0006]
As mentioned above, the ornamental diamond has almost all the pavilion embedded in the pedestal, so the light coming out of the pavilion surface does not reach the observer, and the light reflected by each surface of the pavilion When the light comes out from each surface of the table surface and the crown, the light is observed by the observer.
[0007]
However, as shown in FIG. 12, the quality and the like of the diamond 80 are determined by observing from the direction perpendicular to the generatrix of each surface of the pavilion from the direction of the girdle 82. The color of diamond 80 was sensuously judged compared to master stones with known color grades. In addition, a diamond photo was affixed to the diamond certificate, but the photo was taken close-up on the table and the culet.
[0008]
[Problems to be solved by the invention]
In the appraisal from such a direction, the brightness when observing the gemstone attached to the pedestal cannot be evaluated.
[0009]
Therefore, an object of the present invention is to provide an appraisal method capable of appraising the same characteristics as those observed when observing diamonds cut for decoration, such as ornamental jewelry.
[0010]
[Means for Solving the Problems]
In the method for appraisal of ornamental jewels according to the present invention, the surface of the jewel to be examined that is normally observed is irradiated with white light, and the light reflected in the jewel is observed at a distance from which the surface is normally observed. It is characterized by judging by.
[0011]
It is preferable to perform the appraisal by irradiating white light from the normally observed surface of the appraisal gemstone and taking a photograph from a position where the light reflected in the gemstone is normally observed.
[0012]
In the case of using a diamond cut as a decorative jewel in the method for identifying a decorative jewel according to the present invention, the crown surface and the table surface of the diamond to be identified are irradiated with white light to reflect the light reflected in the diamond. Appraisal is made by observing the table surface and the crown surface from the table surface.
[0013]
Here, the normal observation position is a place where the table surface and each surface of the crown can be seen at a distance of about 200 to 500 mm that is normally observed on the diamond table surface.
[0014]
In the method for identifying a decorative diamond according to the present invention, it is preferable to observe the color of the reflected light. Moreover, it is preferable to take the photograph of the reflected light from a position where it is normally observed.
[0015]
In the appraisal method for ornamental jewelry according to the present invention, it is preferable to attach a photograph taken from a position to be observed normally to the appraisal document.
[0016]
In the method for identifying a decorative diamond of the present invention, it is preferable to irradiate each crown surface and table surface of the diamond to be identified with white light and observe the light transmitted through the diamond from the pavilion surface side. It is preferable to take a photograph of the transmitted light.
[0017]
In the appraisal method for decorative diamond of the present invention, it is preferable that the photograph of the transmitted light is attached to the appraisal document.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
The method for identifying a decorative jewel according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a side view for explaining a method for identifying a decorative jewel according to the present invention.
[0019]
In this figure, a table made of a transparent plate 12 such as a glass plate is provided almost directly above the light source 11 such as white light. A jewelry mount 13 is placed on the transparent plate. The mounting base 13 is provided with a recess in which a gemstone to be identified (for example, diamond 80) can be attached. In the case of diamond, the depression has an inverted conical shape, and has a size that allows the pavilion portion of the diamond 80 to be identified to substantially enter. The diamond 80 to be identified is attached to the recess of the mounting base 13 so that the table faces up. The concave mirror 14 is attached so as to cover the mounting base 13 on which the diamond 80 is placed, and the light 15 emitted from the light source 11 is made incident on each table surface and crown surface of the diamond 80 to be identified. An opening 16 is provided at the upper center of the concave mirror. When the diamond 80 to be identified is positioned directly below the opening 16, the diamond can be observed through the opening 16. On the diamond 80 table, when the diamond table surface is viewed through the opening 16 opened in the concave mirror 14 from a position 200 to 500 mm away from the table, the light emitted from each surface of the table surface and the crown is observed.
[0020]
According to the appraisal method shown in FIG. 1, the light 15 incident on the table surface and each crown surface of the diamond 80 to be identified by the concave mirror 14 is refracted and reflected in the diamond, and the table surface and each crown surface Since the light coming out of is observed, the eyes of the person to be identified are placed at the same position as when the diamond is normally observed, and the evaluation method of the present invention performs the evaluation of the same characteristics as the normal observation. Can do.
[0021]
In FIG. 1, a digital camera 17 is installed at a position 200 to 500 mm above the diamond 80 to be identified, and an image photographed by the digital camera 17 is displayed on the display 18. At this time, it is preferable to place a light shielding tube (not shown) around the optical path between the opening 16 at the top of the concave mirror and the digital camera 17 so that light does not enter the camera from around. By printing the image of the digital camera 17 and attaching it to the appraisal, it is possible to place almost the same image on the appraisal as at the time of observation. Here, the output signal of the digital camera 17 can be input to a personal computer (not shown), and the output signal of the digital camera 17 can be subjected to image processing. By this image processing, the reflected light from the diamond 80 can be spectralized to obtain a spectral distribution for each wavelength of the reflected light. By inputting the output signal of the digital camera 17 to the display 18 together with the personal computer, the reflected light spectrum can be obtained together with the image of the reflected light from the diamond.
[0022]
FIGS. 2 to 5 show traces of photographs showing the reflected light of the diamond thus photographed. Fig. 2 is a photograph of the cut diamond proposed in Japanese Patent Application No. 2000-18146, filed by the present applicant, by the appraisal method shown in Fig. 1. A weak spot is indicated as a2, and a strong light spot is indicated as a3. The most shining part is not hatched. FIG. 3 is a trace of a photograph in which only the blue color is extracted from the image. In FIG. 3, the dark blue part is shown as b1, the halftone part is b2, and the light blue part is shown as b3. As apparent from comparison between FIG. 2 and FIG. 3, the image of FIG. 2 showing the entire light image is almost the same as the image of FIG. 3 in which only the blue color is extracted from the image of FIG. It can be seen that the image shown is mostly made of blue. Fig. 4 is a photograph of a diamond cut by a conventional GIA system, taken by the appraisal method shown in Fig. 1, where a1 is a weak spot of light, a2 is a weak spot of light, and a strong spot of light. It is shown as a3. In addition, the brightest part is not hatched. FIG. 5 is a trace of a photograph in which only the blue color is extracted from the image. Here, the blue halftone is b2, and the light blue is b3. As is clear by comparing FIG. 5 with the image of FIG. 4, it can be seen that almost no blue light is emitted. As is clear from these figures, the cut diamond proposed by the applicant of the present application has a blue light that is stronger than the GIA system cut diamond. On the other hand, a diamond with a conventional cut shows a fine reflected image, but it is a strong monochromatic monochrome.
[0023]
In addition, the degree of diamond shine can be expressed numerically. The sparkle is 1.23 or less for diamonds of D to E colors, which are evaluated as excellent by the AGL cut standard, and 0.95 or less for F to G colors. In order to measure the brightness, a photocell of a photometer is placed at the position of the digital camera 17 in FIG. 1, and the intensity of the brightness is measured. Alternatively, the intensity of the brightness can be measured by scanning the output image from the digital camera 17 in FIG. By placing a diamond whose brightness is to be measured and a calibration diamond with known brightness at the measurement position in FIG. 1 and measuring the intensity of the brightness and comparing them, the brightness can be quantified. .
[0024]
It is also possible to spectralize the reflected light from the diamond and make it a diamond color distribution or color quality. In FIG. 1, white light from the light source 11 is incident on the table surface and crown surface of the diamond 80, and the light reflected and emitted inside the diamond is observed at the position of the digital camera 17 in FIG. The reflected light is dispersed and the intensity spectrum of the reflected light is measured for each wavelength. Since the method of measuring the intensity spectrum is well known in the field of spectroscopic techniques, a detailed description thereof will be omitted. Since this spectrum is determined by the cut, clarity, and color of the diamond, it is characteristic for each diamond. Therefore, it is preferable to put the spectrum of the reflected light on the diamond certificate.
[0025]
The transmitted light of the jewel can be observed by applying the appraisal method of the present invention shown in FIG. FIG. 6 is an explanatory diagram of an apparatus used for the transmitted light observation method. In FIG. 6, the same components as those in FIG. 1 are denoted by the same reference numerals. In FIG. 6, the light source 11, the transparent plate 12, and the digital camera 17 are the same as those in FIG. Here, a mask 41 having an opening 42 sized to receive the diamond 80 observed on the transparent plate is installed, and the diamond 80 is placed in the opening 42 with the table surface down. The optical axes of the light 15 from the light source 11 coincide with each other so as to enter the digital camera 17 through the diamond 80 in the mask opening 42. The digital camera 17 is placed 200 to 500 mm away from the diamond 80.
[0026]
Some of the light incident on the diamond table and crown from the light source is reflected in the diamond, but some emerge from each side of the pavilion and reach the digital camera. Imaging can be performed.
[0027]
FIGS. 7 and 8 show images obtained when the cut diamond proposed by the present applicant and the diamond cut by the conventional GIA system are observed using this apparatus. In these figures, the color of red light is r, the color of yellow light is y, the color of blue light is b2, and the color of blue light is b3. The image in FIG. 7 has a strong red light. However, with the GIA system cut in FIG. 8, blue light appears on the pavilion surface.
[0028]
In the cut diamond proposed in the applicant's already filed application, the reflected light from the table surface and the crown surface is strong in blue light as shown in FIGS. 2 and 3, and the transmitted light from the pavilion is As shown in FIG. 7, the red color is won. However, a conventional GIA-cut diamond has no strong spectrum as shown in FIGS.
[0029]
Thus, according to the appraisal method of the present invention, not only the brightness of the diamond but also the light spectrum inside the diamond can be observed. In the cut diamond proposed by the present applicant in Japanese Patent Application No. 2000-18146, the light incident on each surface of the table and crown is dispersed inside the diamond, and light with a short wavelength close to purple is applied to the table or crown. Light having a long wavelength that is emitted from each surface of the crown and close to red is transmitted to each surface of the pavilion. Even if the color of the observed diamond is yellowish, when viewed from the upper surface of the diamond, it appears as white with strong blue light due to this spectroscopy. This diamond brightness can be measured by the appraisal method according to the present invention.
[0030]
The result of carrying out the method for appraisal of a decorative jewel according to the present invention is described in an appraisal document (that is, a quality certificate) shown in FIG. 9 and attached to the jewel. This certificate includes columns for cut name, weight, quality (color grade, intensity and spectrum of brightness, grade of clarity), explanation of quality standards, photo affixing column, and expert name. In the affixed column of the photo, the plan photo of the diamond explained in FIG. 2 and the bottom photo of the diamond explained in FIG. 7 are pasted, but only the plan photo may be used.
[0031]
Although the above explanation was performed using cut diamond as a decorative gem, it can also be applied to gems other than diamond such as sapphire and ruby.
[0032]
【The invention's effect】
As described above in detail for the method of appraisal of ornamental jewels according to the present invention, the appraisal method of the present invention makes it possible to match observation and appraisal evaluation by identifying ornamental jewels from almost the same viewpoint as actual observation. did it. Furthermore, when the incident light is split inside the gemstone, it is possible to make an appraisal reflecting the characteristic of the spectrum.
[Brief description of the drawings]
FIG. 1 is a side view for explaining a method for identifying a decorative jewel according to the present invention.
2 is a photograph showing the reflected light of diamond photographed by the appraisal method shown in FIG. 1. FIG.
FIG. 3 is a photograph showing only blue light extracted from the photograph of FIG.
4 is a photograph showing the reflected light of diamond photographed by the appraisal method shown in FIG. 1. FIG.
FIG. 5 is a photograph showing only blue light extracted from the photograph of FIG.
FIG. 6 is an explanatory diagram of an apparatus used for a transmitted light observation method.
7 is a photograph showing the transmitted light of diamond imaged by the apparatus shown in FIG.
FIG. 8 is a photograph showing the transmitted light of diamond imaged by the apparatus shown in FIG.
FIG. 9 shows an example of an appraisal showing the result of appraising a decorative gem according to the present invention.
10A and 10B are cut diamonds, wherein FIG. 10A is a plan view thereof, FIG. 10B is a side view thereof, and FIG. 10C is a bottom view thereof.
FIG. 11 is a side view of a diamond attached to a pedestal.
FIG. 12 is a diagram for explaining a conventional appraisal method.
[Explanation of symbols]
11 light sources
12 transparent plate
13 Mounting base
14 concave mirror
15 light
16 openings
17 digital camera
18 displays
41 mask
42 openings
80 diamonds
81 table surface
82 girdle
83 Culet
84 main facets
85 star facet
86 upper girdle facet
87 main facets
88 lower girdle facet
90 pedestal

Claims (3)

Place the diamond on the transparent plate so that the table surface of the diamond to be judged is down,
Irradiate the crown surface of the diamond and the table surface with white light from a light source below the transparent plate,
A method for appraisal of a decorative diamond for appraisal by imaging and observing light transmitted through the diamond with a digital camera above the transparent plate,
Place the diamond on the transparent plate using a mounting base so that the table surface of the diamond is on top,
A concave mirror having an opening is attached to the transparent plate so as to cover the diamond placed on the transparent plate,
Using the concave mirror, irradiate the crown surface and the table surface of the diamond with white light from the light source below the transparent plate,
Further, by capturing and observing an image of the reflected light by the digital camera while covering the optical path between the digital camera above the transparent plate and the opening of the concave mirror with a light shielding cylinder. appraisal method of that decoration for diamond be characterized by the appraisal. The method for identifying a decorative diamond according to claim 1 , wherein the color of light transmitted through the diamond is observed. The method for identifying a decorative diamond according to claim 1 or 2 , wherein the color of the light reflected in the diamond is observed.

Images