JP2002048721A - Appraisal method for decorative gemstone - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an appraisal method capable of grasping the same characteristic as that observed in usual observation of a decorative gemstone, especially of a diamond cut decoratively. SOLUTION: On an ordinary observation face of a gemstone, that is, in the diamond cut decoratively, a table face and crown faces are irradiated respectively with white light, and then, the light reflected in the gemstone is observed or photographed from a usual observation position for appraising the decorative gemstone.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for identifying jewelry for decoration, particularly a new diamond cut for decoration.

[0002]

2. Description of the Related Art Decorative jewels are cut. Diamond 80 has a brilliant cut,
Its shape is as shown in FIG. FIG.
10A is a plan view, FIG. 10B is a side view, and FIG.
Is a bottom view. Here, the upper surface is a table surface 81, and the upper part of the girdle 82 is a crown portion having a substantially truncated cone shape,
The table surface forms the top surface of the truncated cone. Girdle 82
The lower part is a pavilion part having a substantially conical shape, and has a portion called a curette 83 at the apex. There are usually eight main facets 84 on the outer circumference of the crown, with a star facet between the outer circumference of the table and the main facet.
85, and an upper girdle facet 86 is formed between the girdle 82 and the main facet 84. In addition, usually eight main facets 87 are formed on the outer periphery of the pavilion, and a lower girdle facet 88 is formed between the girdle and the main facet.

[0003] The 4C used for the evaluation of diamond is:
Carat (weight), color, clarity, and cut. Of these, carat, color, and clarity are properties that the stone originally has and cannot be modified by humans. The brightness can be changed by the way of cutting. For this purpose, various cuts have been considered and applied to jewelry.

[0004] The decorative jewel is cut and attached to a pedestal. For example, as shown in FIG. 11, a diamond 80 has a pavilion portion embedded in a pedestal 90, and a crown portion above a 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 not visible from the outside of the pedestal 90.Through the table and crown, the pavilion can be cut from above. It is only observed.

[0005] The reason that the diamond viewed from the table is shining and observed is that the light incident from the table surface and each surface of the crown is refracted and reflected inside the diamond, and the light emerging from the diamond crown and the table is observed. In order to reach those.

[0006] Decorative diamonds, as mentioned above,
Since the pavilion part is almost embedded in the pedestal,
Light coming out of the pavilion surface does not reach the observer, and the light reflected on each surface of the pavilion is observed by the observer when it comes out of the table surface or crown surface. Become.

However, as shown in FIG. 12, the quality of the diamond 80 and the like were determined by observing the girdle 82 from a direction perpendicular to the generatrix of each surface of the pavilion. The color of the diamond 80 was sensually judged as compared to the master stone of known color grade. In addition, a photograph of a diamond was stuck on a diamond certificate, but the photograph was taken in close-up from a table surface and a curette.

[0008]

In such an appraisal from the above, it is not possible to evaluate the brightness when observing the jewel mounted on the pedestal.

Accordingly, an object of the present invention is to provide an appraisal method capable of discriminating the same characteristics as those observed when observing diamonds, particularly ornamental cut diamonds, such as ornamental jewels.

[0010]

According to the method of the present invention, a normally observed surface of a jewel to be examined is irradiated with white light, and light reflected in the jewel is reflected from the surface. Characterization is performed by observing at a normal observation distance.

[0011] It is preferable to irradiate white light from a normally observed surface of the jewel to be identified and take a photograph from a position where the light reflected in the jewel is normally observed for identification.

When diamonds cut as ornamental jewels are used in the ornamental jewelry appraisal method of the present invention, white light is applied to each surface of the crown and the table surface of the appraised diamond to reflect the diamond. The light is identified by observing the table surface and each surface of the crown from above the table surface.

Here, the normal observation position means a normal observation distance of about 200 to 500 m on the diamond table surface.
m This is a place where you can see the table surface and each surface of the crown at a distance.

In the method of the present invention for identifying a decorative diamond, it is preferable to observe the color of the reflected light. Further, it is preferable to take a picture of the reflected light from a position where it is normally observed.

In the method for judging a decorative jewel according to the present invention,
It is preferable to affix a photograph taken from a position for normal observation to an appraisal report.

In the method for appraising a decorative diamond according to the present invention, it is preferable to irradiate white light on each of the crown surface and the table surface of the test diamond and observe the light transmitted through the diamond from the pavilion surface side. Also,
Preferably, a picture of the transmitted light is taken.

In the method of the present invention for identifying decorative diamonds, it is preferable that the photograph of the transmitted light is attached to an identification document.

[0018]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a method for judging a decorative jewel according to the present invention. FIG. 1 is a side view for explaining a method for judging a decorative jewel according to the present invention.

In this figure, a table made of a transparent plate 12 such as a glass plate is provided almost directly above a light source 11 such as white light. On a transparent plate, a mount 13 for jewelry is placed. The mounting base 13 is provided with a recess in which a jewel (for example, diamond 80) to be identified can be mounted. The depression has an inverted conical shape in the case of diamond,
The size of the pavilion of the diamond 80 to be assessed is approximately large. The diamond 80 to be identified in the recess of the mounting base 13 is mounted with its table facing upward. The concave mirror 14 is attached so as to cover the mounting table 13 on which the diamond 80 is placed, and the light 15 emitted from the light source 11
Is incident on each of the table surface and the crown surface of the diamond 80 to be identified. An opening 16 is provided in the center of the upper part of the concave mirror, and when the diamond 80 to be identified is positioned directly below the opening 16, the diamond can be observed through the opening 16. On a diamond 80 table, place a concave mirror 14 from a position 200 to 500 mm away from the table.
When the diamond table surface is viewed through the opening 16 formed in the table, light emitted from the table surface and the crown surface is observed.

According to the appraisal method shown in FIG. 1, the light 15 incident on each of the table face and the crown face of the diamond 80 to be discriminated by the concave mirror 14 is refracted and reflected in the diamond, and the table face, Since the light coming out of each face of the crown is observed, the eye of the person who is appraising the diamond at the same position as when normally observing the diamond is placed, and the appraisal of the same characteristics as the normal observation is performed by the appraisal method of the present invention Can be implemented.

In FIG. 1, a digital camera 17 is installed at a position 200 to 500 mm away from a diamond 80 to be identified, and an image taken by the digital camera 17 is displayed on the display.
18 is displayed. At this time, it is preferable to provide a light shielding tube (not shown) around the optical path between the opening 16 above the concave mirror and the digital camera 17 so that light does not enter the camera from around. Digital camera 17
By printing the image and attaching it to the certificate,
An image almost the same as that at the time of observation can be put on the appraisal report. 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 converted into a spectrum 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.

FIGS. 2 to 5 show traces of photographs showing the state of reflected light of the diamond taken in this manner. Fig. 2 shows a Japanese Patent Application No. 2000-1 filed by the present applicant.
Figure 8 shows a photograph of a diamond with a cut proposed in No. 8146, using the identification method shown in FIG. 1.
3 is shown. The brightest parts are not hatched. FIG. 3 is a trace of a photograph in which only blue is extracted from the image. In FIG. 3, dark blue light is indicated as b1, halftone is indicated as b2, and light blue is indicated as b3. As is clear from a comparison between FIG. 2 and FIG. 3, the image of FIG.
Since the image of FIG. 2 is almost the same as the image of FIG. 3 in which only blue is extracted, it can be seen that the image shown in FIG. 2 is almost made of blue. FIG. 4 shows a diamond that has been cut by a conventional GIA system photographed by the identification method shown in FIG. 1. Indicated as a3. Also, the brightest part is not hatched. FIG. 5 is a trace of a photograph in which only blue is extracted from the image. Here, b2 is for a blue halftone and b3 is for a pale blue. As is clear from the comparison of 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 present applicant in the already filed application emits more blue light than the cut diamond of the GIA system. On the other hand, a diamond that has been cut in the past has a fine reflection image, but is a black and white monochromatic strong one.

Also, the degree of shine of the diamond can be expressed numerically. The brightness is D-E color diamond which is evaluated as excellent by AGL cut standard 1.
23 or less, 0.95 or less for FG color. To measure the brightness, a photocell of a photometer is placed at the position of the digital camera 17 in FIG. 1, and the brightness is measured. Or,
In FIG. 1, the output image from the digital camera 17 can be scanned to measure the brightness. By placing the diamond whose brightness is to be measured and the calibration diamond whose brightness is known at the measurement position in FIG. 1, measuring the brightness of the brightness and comparing them, the brightness can be quantified. .

The spectrum of the reflected light from the diamond can be used as the color distribution or color quality of the diamond. In FIG. 1, white light from the light source 11 is made incident on the table surface and the crown surface of the diamond 80,
The light reflected from the inside of the diamond is observed at the position of the digital camera 17 in FIG. 1, the reflected light is separated, and the intensity spectrum of the reflected light is measured for each wavelength. The method of measuring the intensity spectrum is well known in the field of spectroscopic technology, and thus will not be described in detail. Since this spectrum is determined by the diamond's cut, clarity, color, etc., each diamond is distinctive. Therefore, it is preferable that the spectrum of the reflected light be also included in the diamond appraisal report.

The transmitted light of the jewel can be observed by applying the identification method of the present invention shown in FIG. FIG. 6 is an explanatory view of an apparatus used for a transmitted light observation method. 6, the same components as those in FIG. 1 are indicated by the same reference numerals.
6, a light source 11, a transparent plate 12, and a digital camera 17 are the same as those in FIG. Here, a mask 41 having an opening 42 large enough to receive a diamond 80 to be observed on a transparent plate is provided, 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 are coincident so that the light 15 enters the digital camera 17 through the diamond 80 of the mask opening 42. The digital camera 17 is placed at a position 200 to 500 mm away from the diamond 80.

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 surface of the pavilion and reach the digital camera. Observation and imaging.

FIGS. 7 and 8 show images obtained by observing the cut diamond proposed by the present applicant and the cut diamond of the conventional GIA system using this apparatus. . In these figures, the color is indicated by r for red light, y for yellow light, b2 for halftone of blue light, and b3 for light blue light. The image in FIG. 7 has a strong red light. However, in the case where the GIA system shown in FIG. 8 is cut, blue light is emitted on the pavilion surface.

As shown in FIGS. 2 and 3, the cut diamond proposed by the applicant of the present invention has strong blue light as reflected from the table surface and the crown surface as shown in FIGS. As shown in FIG. 7, the transmitted light has a red color. However, in the conventional GIA cut diamond, as shown in FIGS.

As described above, according to the evaluation method of the present invention, not only the brightness of the diamond but also the spectrum of light inside the diamond can be observed. Applicant filed Japanese Patent Application 2000
In the diamond with the cut proposed in -18146, light incident on each surface of the table and crown is split inside the diamond, and light with a short wavelength close to purple is emitted from each surface of the table and crown, Light of a long wavelength close to red is transmitted through each surface of the pavilion. Even if the color of the diamond observed is yellowish, when viewed from the upper surface of the diamond, the diamond looks strong white with blue light because of this spectrum. The brightness of the diamond can be measured by the identification method according to the present invention.

The result of implementing the method for appraising a decorative jewel of the present invention is described in an appraisal certificate (ie, a quality certificate) shown in FIG. 9 and attached to the jewel. This certificate contains the name of the cut,
There are columns for weight, quality (color grade, shine intensity and spectrum, clarity grade), explanation of quality standards, photo pasting section, and appraiser name section. The plan view of the diamond described in FIG. 2 and the bottom view of the diamond described in FIG. 7 are pasted in the photo pasting column, but only the plan view may be used.

Although the above description has been made using cut diamonds as decorative jewels, the present invention can also be applied to jewels other than diamonds, such as sapphire and ruby.

[0032]

As described above, the method for appraising ornamental jewelry according to the present invention has been described in detail, and the appraisal method of the present invention assesses ornamental jewelry from almost the same viewpoint as actual observation, thereby evaluating observation and appraisal. Was able to match.
Further, when the splitting of the incident light occurs inside the jewel, it is possible to make the judgment reflecting the characteristic of the splitting light.

[Brief description of the drawings]

FIG. 1 is a side view for explaining a method for judging a decorative jewel according to the present invention.

FIG. 2 is a photographic diagram showing reflected light of a diamond taken by the appraisal method shown in FIG.

FIG. 3 is a photographic view obtained by extracting only blue light from the photographic view of FIG. 2;

FIG. 4 is a photographic view showing reflected light of a diamond taken by the appraisal method shown in FIG.

FIG. 5 is a photographic diagram showing only blue light extracted from the photographic diagram of FIG. 4;

FIG. 6 is an explanatory diagram of an apparatus used for a transmitted light observation method.

FIG. 7 is a photographic view showing transmitted light of diamond taken by the apparatus shown in FIG. 6;

8 is a photographic view showing transmitted light of a diamond taken by the apparatus shown in FIG. 6;

FIG. 9 shows an example of an appraisal report showing the results of appraisal of decorative jewelry according to the present invention.

FIG. 10 shows a cut diamond.
(A) is a plan view, (B) is a side view, and (C) is a bottom view.

FIG. 11 is a side view of a diamond attached to a pedestal.

FIG. 12 is a diagram illustrating a conventional appraisal method.

[Explanation of symbols]

 11 Light source 12 Transparent plate 13 Mounting base 14 Concave mirror 15 Light 16 Aperture 17 Digital camera 18 Display 41 Mask 42 Aperture 80 Diamond 81 Table surface 82 Girdle 83 Culett 84 Main facet 85 Star facet 86 Upper girdle facet 87 Main facet 88 Lower girdle facet 90 pedestal

Claims (10)

[Claims] An ornamental jewel is characterized in that white light is emitted from a normally observed surface of the jewel to be identified, and the light reflected in the jewel is observed from the surface to identify the jewel. Appraisal method. 2. The method according to claim 1, wherein a white light is emitted from a normally observed surface of the jewel to be identified, and a photograph is taken from a position where the light reflected in the jewel is normally observed for identification. The method for identifying a decorative jewel according to claim 1. 3. Appraisal is made by irradiating white light on each of the crown surface and the table surface of the diamond to be identified, and observing the light reflected in the diamond by viewing the table surface and the crown surface from the table surface. A method for identifying a decorative diamond. 4. The method according to claim 3, wherein the color of the reflected light is observed. 5. The method according to claim 3, wherein a photograph of the reflected light is taken from a position where the reflected light is normally observed. 6. A method for appraising a decorative jewel according to claim 1, wherein a photograph taken from a normally observed position is attached to an appraisal report. 7. An ornamental diamond appraisal characterized by irradiating each face of the crown and the table face of the appraisal diamond with white light, and observing light transmitted through the diamond from a pavilion face side. Method. 8. The method according to claim 7, wherein the color of the transmitted light is observed. 9. The method according to claim 7, wherein a photograph of the transmitted light is taken. 10. The method according to claim 9, wherein a photograph of the transmitted light is attached to an appraisal report.