WO2020027006A1

WO2020027006A1 - Cut diamond and method for manufacturing same

Info

Publication number: WO2020027006A1
Application number: PCT/JP2019/029556
Authority: WO
Inventors: 木下顕伸
Original assignee: 木下顕伸; 国際興建株式会社
Priority date: 2018-07-31
Filing date: 2019-07-27
Publication date: 2020-02-06

Abstract

There has been a demand for a round-cut diamond in which light entering from the crown, in particular a table facet, is totally reflected by the pavilion and emitted from even the girdle, such that a linear light or linear dark area can be observed; and a method for cutting the same. In order to solve such problems, the present invention provides, as a first invention, a round-cut diamond comprising girdle facets inclined 0.1 to 45 degrees inclusive (but limited to an angle smaller than the angle formed by a crown face and the center axis) outward from the crown with respect to a central axis passing through the girdle from the center of the table facet to the center of the culet surface, the girdle facets reducing the total reflection (that is, the re-reflection into the diamond) of light beams that entered from the table facet and then were reflected from the pavilion-side facets, and increasing the emitted light from the girdle.

Description

Cut diamond and method for producing the same

The present invention relates to a method for producing a cut diamond, which is a cut diamond, and an invention relating to the cut diamond.

In the conventional cut diamond, the girdle at the boundary between the crown and the pavilion was cut in parallel with the normal direction of the table facet, that is, in such a way that the diamond became vertical when the diamond was erected. This configuration is inevitably customary because it is necessary to firmly fix the diamond when cutting the diamond. However, the girdle surface processed in this manner was optically inefficient, and could not efficiently utilize the light from the table facets, which was the main intake of the light emitted by the diamond.

The light entering the diamond from the crown, especially the table facet, is totally reflected by the pavilion and is also emitted from the girdle part, and a round cut is made so that linear light can be observed or linear dark areas can be observed. There has been a demand for a diamond that has been made and a method for cutting the diamond.

In order to solve such a problem, the present invention provides, as a first invention, a girdle that is 0.1 degrees or more and 45 degrees outside the crown with respect to a center axis extending from the center of the table facet to the center of the culet plane ( However, the crown surface is limited to an angle smaller than the angle formed by the central axis. The girdle facet is inclined below, and total reflection of the light beam incident from the table facet and reflected by the pavilion side facet (that is, re-reflection into the diamond) ) Is reduced by a girdle to provide a round-cut diamond having a girdle facet with more light emitted from the girdle.

Next, as a second invention, the girdle is inward of the crown from the center of the table facet to the center of the culet surface by 0.1 to 45 degrees inside the crown (however, the angle formed by the pavilion surface with the center axis). Provided is a girdle facet having a girdle facet which is constituted by a girdle facet which is inclined below, and which has a girdle that increases the total reflection of a light beam incident from a table facet and reflected by a pavilion side facet.

Next, as a third invention, the width of the girdle facet is 0.2% or more and 10% or less with respect to the height between the curette face and the table facet. Provide round diamonds.

Next, as a fourth invention, each facet other than the table facet of the crown is arranged asymptotically with respect to the center axis in a table facet front view, and each facet except the culet of the pavilion is the center axis. The round-cut diamond according to any one of the first invention to the third invention, which is arranged point-symmetrically with respect to.

Next, as a fifth invention, the table facets are 9-sided, the number of facets constituting the crown excluding the girdle facets is 54 excluding the table facets, and the number of facets constituting the pavilion is The round cut according to any one of the first to fourth inventions, in which the number of facets is 32 without counting the culet as a surface except for the girdle facet, and the total number of facets is 88 including the table facet and the girdle facet. Offer diamonds.

Next, as a sixth invention, the table facet is a pentagon, the number of facets constituting the crown excluding the girdle facet is 36 excluding the table facet, and the number of facets constituting the pavilion is The round-cut diamond according to any one of the first to fourth inventions, wherein the number of facets is 25, excluding the girdle facets, and the number of facets is 25 including the table facets and the girdle facets. I will provide a.

Next, as a seventh invention, the girdle is disposed at an angle of 0.1 to 45 degrees outward of the crown with respect to a center axis extending from the center of the table facet to the center of the culet surface (however, the angle formed by the crown surface with the center axis). The girdle facet is composed of a girdle facet that is tilted below, and the total reflection of the light beam incident from the table facet and reflected by the facet on the pavilion side is reduced with a girdle, and the girdle facet is designed with a rough diamond or other cuts Provided is a method for producing a round-cut diamond by grinding formed diamond.

Next, as an eighth invention, the girdle is placed at an angle of 0.1 degree or more and 45 degrees inward of the crown with respect to a center axis passing from the center of the table facet to the center of the culet surface (however, the angle formed by the pavilion surface with the center axis). The girdle facet is composed of a girdle facet that is tilted below, and the total reflection of the light beam incident from the table facet and reflected by the facet on the pavilion side is increased with a girdle, designed with a rough diamond or other cuts Provided is a method for producing a round-cut diamond by grinding formed diamond.

Next, as a ninth invention, the width of the girdle facet is designed by a rough diamond or another cut so that the width between the curette face and the table facet is 0.2% or more and 10% or less. A method for producing a round-cut diamond according to the seventh or eighth invention, wherein the round diamond is formed by grinding.

Next, as a tenth invention, each facet other than the table facet of the crown is designed by a rough diamond or another cut so as to be arranged asymptotically with respect to the central axis in a table facet front view. A method for producing a round-cut diamond according to the seventh or ninth invention, wherein the diamond is ground.

Next, as an eleventh invention, the table facet is a nine-sided shape, the number of facets constituting the crown excluding the girdle facet is 54 except for the table facet, and the number of facets constituting the pavilion is: Except for the girdle facet, the surface is 32 without counting the curette as a surface, and the diamond is designed by grinding a rough diamond or another cut so that the total number of facets is 88 including the table facet and the girdle facet. A method for producing a round-cut diamond according to any one of the seventh to tenth aspects of the present invention.

Next, as a twelfth invention, the table facets are 9-sided, the number of facets constituting the crown excluding the girdle facets is 36 excluding the table facets, and the number of facets constituting the pavilion is: Excluding the girdle facet, the curette is counted as a surface, and the surface is 25 surfaces, and the diamond is designed by grinding a rough diamond or other cut so that the total number of facets is 63 surfaces including the table facet and the girdle facet. The method for producing a round-cut diamond according to any one of the seventh to tenth inventions.

Since the girdle surface of the diamond provided by the present invention is not parallel to the central axis but cut at an angle, the light internally reflected by the pavilion can be emitted more than the conventional diamond. It becomes possible, or it becomes possible to emit less light internally reflected by the pavilion than conventional diamonds, so that the surrounding facets, especially the facet of the pavilion in the former configuration, and the facet of the crown in the latter configuration The brightness difference has become clearer, and it is now possible to enjoy a circular linear shine that has never been seen before. In addition, by limiting the angle of the girdle surface, stones can be mechanically held during diamond cutting, can be fixed with nails when placed on decorations such as rings, and are hard to scratch, Can contribute.

Diagram showing ideal diamond cut configuration with 58 faces cut Diagram showing the inclination of the girdle facet with respect to the central axis in the normal direction on the table facet The figure showing the fluctuation of the amount of light taken in according to the inclination of the facet with respect to the central axis in the normal direction to the table facet Diagram showing the relationship between light reflection and total reflection Conceptual diagram showing reflection inside a diamond The figure which shows the relationship of the incident angle of the incident light with respect to a pavilion side facet and a girdle facet when the girdle facet has no inclination. The figure which shows the relationship of the incident angle of the incident light with respect to a pavilion facet and a girdle facet when the girdle facet has an inclination outside the lowermost edge of the crown. The figure which shows the relationship of the incident angle of the incident light with respect to a pavilion side facet and a girdle facet when the girdle facet has a slope inside the lowermost edge of the crown. Example of reflected light from the crown facet when the table facet is point symmetric Example of reflected light from the crown facet when the table facet is asymmetric Diagram showing ideal diamond cut configuration with 88 faces Reproduced image showing experimental results showing the reflection mode of diamond with a cut surface of 88 Reproduced photograph of experimental results showing the reflection mode of diamond with 58 faces cut Diagram showing ideal diamond cut configuration with 63 faces cut Figure that reproduces the experimental result photograph showing the reflection mode of diamond with 63 cuts Table showing the results of a questionnaire comparing the apparent intensity of the brightness of the conventional cut diamond with the cut diamonds of Embodiments 5 and 6. Table showing the results of a questionnaire comparing the apparent preference between the design of the conventional cut diamond and the designs of the cut diamonds of Embodiments 5 and 6.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the first embodiment is described in

claims

1 and 1, the second embodiment is described in claim 2, the third embodiment is described in claim 3, the fourth embodiment is described in claim 4, and the fifth embodiment is described in claim 4. In claim 5, embodiment 6 is in claim 6, embodiment 7 is in claim 7, embodiment 8 is in claim 8, embodiment 9 is in claim 9, embodiment 10 is in claim 10, Embodiment 11 corresponds to claim 11 and embodiment 12 corresponds to claim 12. The contents of the present invention are not limited only to the following embodiments, and various changes can be made without departing from the gist of the present invention.

<First embodiment>
<First Embodiment Outline of the Invention>
According to the invention in this embodiment, the girdle is disposed at an angle of 0.1 degree or more and 45 degrees outside the crown with respect to a center axis extending from the center of the table facet to the center of the culet surface (however, the angle between the crown surface and the center axis is smaller than 45 degrees). This is a round cut diamond having a girdle facet which is constituted by a girdle facet which is inclined below, and which has a girdle to reduce the total reflection of a light beam incident from a table facet and reflected by a pavilion side facet.

<First Embodiment Configuration of the Invention>
As shown in FIG. 1, a facet of a round-cut diamond in the present embodiment (conventionally, it refers to a diamond-viewable plane created by grinding a rough stone, but in the present application, refers to a diamond-viewable surface. , A curved surface typified by a girdle facet is also included.) The area above the girdle including the largest facet (0101) is called a crown (0102), and the area below the girdle is a pavilion (0103).
The light exit surface of the diamond of the present invention includes a table facet in the crown, a crown facet (0104) other than the table facet in the crown, a girdle facet (0105) that has not been conventionally used as a light exit surface, and a pavilion side. Then, there are a culet at the bottom (only when chamfered; may or may not be chamfered) (0106) and a pavilion-side facet (0107) excluding the culet. The feature of the round-cut diamond in the present embodiment is that the girdle is 0.1 degrees or more and 45 degrees outside the lowermost edge of the crown (0108) with respect to the center axis extending from the center of the table facet to the center of the culet plane (however, A girdle facet which is constituted by a girdle facet which is inclined below and whose total reflection of a light beam incident from the table facet and reflected by the pavilion side facet is reduced by a girdle is limited to an angle smaller than the angle formed by the crown surface with the central axis. Have.

`` Round cut '' is a typical cutting of diamonds, when the cut diamond is viewed from above, the outline is circular, and when viewed from the side, the trapezoid of the crown rides on the inverted triangle of the pavilion, It refers to cutting where many planes are cut out. The most common type of round cut is a round brilliant cut. The present invention is a round cut, and basically a line connecting the center point of the table facet and the center point of the curette is a line parallel to the normal of the table facet.

Fig. 2 shows how to measure the inclination of the girdle facet with respect to the central axis. FIG. 2a shows the inclination (θ1) of the girdle facet with respect to a straight line (C′-C ′) parallel to the central axis (CC) when the girdle facet protrudes from the crown. θ1 is an angle in the range of 0 ° to 90 ° outside the lowermost edge of the crown with respect to the center axis, and is 0.1 ° or more and 30 ° or less in the present embodiment.

Assuming that the scattered light is uniformly incident on any facet on the crown side of the diamond (this assumption is approximately correct for typical diamond wear), the light exiting from any facet of the diamond is uniform The light is emitted as scattered light. This is because when the diamond is worn with it placed on the ring, the pavilion side is the metal ring that constitutes the ring, and the incident light is relatively small or biased because it is the skin side of the finger, but the crown is This is because it is generally considered that light is uniformly incident on the side because there are not so many that block light. Since the light incident on the crown side is reflected on the pavilion side, the light emitted from the crown-side facet is represented by the normal direction of the center of gravity of the facet (the line having the highest brightness during observation: hereinafter, “representative”). Light.) The crown facet having the largest amount of incident light is a table facet.

(3) As shown in FIG. 3, the light uptake increases as the inclination of the facet approaches 90 degrees with respect to the central axis (that is, as the plane approaches the table facet). This is based on the assumption that the sunlight is generally evenly radiated from above the head, or that the lighting equipment is generally placed above the head indoors. That is, the luminous flux density of the luminous flux incident on the diamond is generally considered to be maximum in the central axis direction. The area on the right side with respect to the 0-degree axis shows the case where the girdle facets protrude outside the lowermost edge of the crown. The amount of light taken in when the girdle facets protrude outside the lowermost edge of the crown increases or decreases in accordance with a change from 0 degrees to 90 degrees on the right as shown in FIG.

As shown in FIG. 4, the light from the optically dense medium 2 of refractive index larger n _2, when joining optically sparse medium 1 small refractive index n _1, the refractive angle than the incident angle i Since r is larger, the refraction angle may be 90 ° for a certain value of the incident angle. If the incident angle at this time is i ₀ , the law of refraction n · sin θ = A (constant numerical value)
Than,
_{_{_{n 2 sini 0 = n 1 sin90}}} °
And the relationship holds.
Therefore,
sini ₀ = n ₁ / n ₂
It can be expressed as.
When the medium 1 is vacuum,
sini ₀ = 1 / n ₂
Becomes
When the angle of incidence is larger than i _0, there is no refracted light beam but only a reflected light beam. This phenomenon is called “total reflection”, and the incident angle i _{0 at} which total reflection occurs is called “critical angle” of the medium 2 with respect to the medium 1.

In diamond, the optically sparse medium 1 is air, and the optically dense medium 2 is diamond. Therefore, when light is taken into the diamond from the air, total reflection does not decrease, but when light is emitted from the diamond to the air, total reflection can be caused. . Although realization is not realistic, there is a case where the diamond is evaluated based on an ideal cut diamond. The reflection characteristics of this ideally cut diamond are such that light entering from the crown side, including the table facets, is not repeatedly emitted from the pavilion side, so that total reflection is repeatedly generated inside the pavilion (or only once). However, it is assumed that all the captured light is emitted from the crown side. That is, no matter what angle the light is taken in from the crown side, the entire surface of the diamond with respect to the central axis in the normal direction is placed on the table surface so that the angle of incidence on the surface of the pavilion is larger than the critical angle of the diamond with respect to air. It is to configure the facet slope.

The critical angle of the diamond is 24.4 °, and the angle of incidence when the light taken into the diamond from the crown side and the girdle facet (the area shown by g in FIG. 5) is reflected by any facet of the pavilion is 24 degrees. When it is less than .4 °, total reflection occurs. FIG. 5 is a conceptual diagram of reflection inside the diamond. θa, θb, θc, θd are incident angles of the light taken from the crown side with respect to the facets of the pavilion. Since θa, θb, and θc are all smaller than the critical angle 24.4 ° of diamond with respect to air, total reflection occurs. The angle of reflection at the time of total reflection is equal to the angle of incidence. On the other hand, since θd is an acute angle greater than 24.4 °, light is emitted from the diamond into the air without total reflection.

The girdle facet is a rounded conical side surface. FIG. 6 is a reflection diagram when there is no inclination in the girdle facet area (indicated by g in the figure) (that is, the inclination is 0 degree with respect to the central axis). The figure shows a region of the pavilion-side facet that totally reflects when light reflected from the pavilion-side facet is incident on the center of the girdle facet and a region of the pavilion-side facet that emits light. When reflected light (hereinafter, referred to as “maximum incident angle reflected light”) enters the center of the girdle from the pavilion facet closest to the culet, the incident angle becomes maximum. A region where the light is incident from the pavilion facet at the center of the girdle facet at an angle of incidence smaller than the critical angle of the diamond with respect to air at 24.4 degrees (hereinafter, referred to as a critical incident angle reflected light) is defined as an emission region. Become. FIG. 7 shows a case where the girdle facet (the area indicated by g in the figure) has an inclination outward from the lowermost edge of the crown (that is, the inclination is 0.1 to 45 degrees outward with respect to the central axis). FIG. As shown in the figure, the maximum incident angle reflected light and the limited incident angle reflected light match. From this, it is recognized that when the girdle facet is inclined outside the lowermost edge of the crown, the critical incident angle reflected light is shifted so as to approach the maximum incident angle reflected light. Then, since there is a critical angle in both the right and left directions with respect to the perpendicular of the girdle facet, the emission area spreads over the entire pavilion facet in the figure. Therefore, when the girdle facet is inclined outside the lowermost edge of the crown, the reflection area is reduced and the emission area is expanded. Since the emission area is expanded, the amount of light emitted from the girdle facet increases. For this reason, the girdle facets of the round-cut diamond according to the present embodiment clearly shine in a crown shape as compared with the round-cut diamond having a girdle without inclination. For this reason, the diamond shines in a direction not seen in the conventional diamond.

The girdle facet is also a part for fixing a diamond ore or a cut diamond that has already been cut when cutting diamond ore or a cut diamond that has already been cut. In order to fix the fixture, a girdle having a surface parallel to the normal of the table facet is ground like a conventional girdle. Therefore, when cutting a diamond ore or a cut diamond that has already been cut, the diamond is first gripped by the girdle to finish the processing of the crown facet and / or the pavilion side facet, and then the girdle facet (with the table facet normal and It is preferable to use a work procedure for processing a non-parallel surface). In particular, it is desirable to process the girdle facet at the earliest after the crown facet is completed. The acute angle formed by a line parallel to the table facet normal of the crown side facet is generally preferably 53.5 to 58.5 degrees (also in the present invention), but is more preferably 58.5 degrees than the acute angle 58.5 degrees. May also be large. For example, it has been found that 58.5 degrees or more and 75 degrees or less, more preferably about 63 degrees plus or minus 1 degree. As described above, when the angle of the crown-side facet is increased, the amount of light that enters from the crown-side facet increases, and the amount of light emitted from the table facet further increases. In general, the angle of the pavilion facet on the acute angle side with respect to the normal direction of the table facet is preferably about 48.2 degrees to 49.4 degrees (also in the present invention). This angle is an angle suitable for the light beam incident from the table facet to be totally reflected by the pavilion-side facet and to exit from the crown-side facet and the table facet again. Also, when looking up the cut diamond, the ratio of the area of the table facet to the area of the crown side facet is preferably 52% to 62%: 38% to 48%, but the table facet normal of the crown side facet is suitable. When the angle on the acute angle side that forms a line parallel to is large, for example, when the angle on the acute angle side is greater than 58.5 degrees, the incident amount of the luminous flux that can be totally reflected by the pavilion-side facet increases. The proportion occupied by facets may be less than 52%. For example, it may be about 25% to 52%. In this case, the light emitted from the diamond is represented in the normal direction from the position of the center of gravity of each facet, so that the diamond is configured such that the glitter is concentrated in substantially the same direction.

<Embodiment 2>
<Embodiment 2 Outline of the invention>
According to the invention in this embodiment, the girdle is placed at an angle of 0.1 ° or more and 45 ° inside the lowermost edge of the crown with respect to a central axis extending from the center of the table facet to the center of the culet surface (however, the pavilion surface forms the central axis). This is a round cut diamond having a girdle facet which is constituted by a girdle facet which is inclined below, and which has a girdle to increase the total reflection of a light beam incident from a table facet and reflected by a pavilion side facet.

<Embodiment 2 Configuration of the Invention>
The round-cut diamond according to the present embodiment is formed such that the girdle is 0.1 to 45 degrees inward of the crown with respect to the center axis extending from the center of the table facet to the center of the culet surface (however, the angle formed by the pavilion surface and the center axis). The girdle facet is constituted by a girdle facet which is inclined below, and the total reflection of the light beam incident from the table facet and reflected by the pavilion side facet is increased by the girdle. The description of the configuration common to the first embodiment is omitted, and only the configuration characteristic of the present embodiment will be described.

FIG. 2b shows the inclination (θ2) of the girdle facet with respect to a straight line (C′-C ′) parallel to the central axis (CC) when the girdle facet is recessed inside the crown. −θ1 is an angle in the range of 0 ° to 90 ° inward with respect to the central axis, and in the present embodiment, is 0.1 ° or more and 30 ° or less inward from the lowermost edge of the crown.

(3) The area on the left side of the 0-degree axis shown in FIG. 3 indicates the case where the girdle facet is recessed inward from the lowermost edge of the crown. The amount of light taken in when the girdle facet is recessed from the crown increases or decreases in accordance with a change from 0 degrees to 90 degrees on the left side as shown in FIG. In the present embodiment, the angle of the girdle facet is the amount of light taken in between 0.1 degrees and 30 degrees in both the left and right directions as shown in FIG.

FIG. 8 shows a case where the girdle facet (the area indicated by g in the figure) is inclined inward from the lowermost edge of the crown (that is, the inclination is 0.1 to 45 degrees inward with respect to the central axis). FIG. As shown in the figure, the limit incident angle reflected light is reflected light from the boundary between the pavilion facet and the girdle facet. Accordingly, when the girdle facet is inclined inside the lowermost edge of the crown, the maximum incident angle reflected light and the limited incident nuclear reflected light are smaller than those of the conventional diamond having no girdle facet shown in FIG. The distance spreads. Since the limit incident angle reflected light approaches the contact point between the pavilion-side facet and the girdle facet, the reflection area of the pavilion-side facet expands, and the emission area decreases. Since the emission area is reduced as compared with the conventional diamond, the amount of light emitted from the girdle facet decreases, and the number of irregular reflections in the diamond increases. For this reason, the contrast between the crown-side facet and the girdle (facet) becomes clearer than that of a conventional diamond in which the girdle facet has no inclination, and the brightness of the emission surface is further emphasized. Therefore, it is evaluated as a more beautiful diamond by an observer as compared with a conventional diamond.

<Embodiment 3>
Embodiment 3 Summary of the Invention
The invention according to the present embodiment is characterized in that the width of the girdle facet is 0.2% or more and 10.0% or less as a ratio to the height between the curette surface and the table facet, in addition to the features of the first or second embodiment. It is a limited diamond.

<Embodiment 3 Configuration Description>
In the diamond according to the present embodiment, in addition to the configuration according to the first or second embodiment, the width of the girdle facet is 0.2% or more and 10% or less with respect to the height between the culet and the table facet. is there. As shown in FIG. 3, the amount of light taken in by each facet increases as the facet is turned 90 degrees with respect to the center axis, that is, parallel to the table facet, with the diamond table facet facing upward. When diamonds are displayed at jewelry stores, they are usually displayed with the table facet facing heaven, and in this state, the proof is poured from the ceiling, that is, from the ceiling. In addition, when a person wears a diamond ring, the diamond attached to the finger is noticeable when the finger is lifted to the upper body, but the diamond table facet held by the finger in many postures Will be turned. For example, when holding an object in your hand, placing your hand on the table, just before shaking hands with an opponent, eating with a knife or fork in your hand, in many cases the table facet Turn around. Therefore, it is preferable that the diamond be cut so that the diamond shines best with the table facet facing upward. Then, the girdle facet located on the side surface of the diamond is a portion where the amount of light taken in is small in the first place. Therefore, the more the girdle facet occupies the entire diamond, the smaller the light uptake. Therefore, the width of the girdle facet is preferably 10% or less of the height between the culet and the table facet. On the other hand, the glow in the horizontal direction is best emitted by the girdle facet, which is a facet in the horizontal direction. Otherwise, it is difficult to visually recognize the linear light trace. Therefore, the width of the girdle facet is preferably at least 0.2% of the height between the curette and the table facet.

<Embodiment 4>
<Embodiment 4 Summary of the invention>
The invention of the present embodiment is characterized in that, in addition to the features of the first to third embodiments, each facet except for the table facet in the crown is arranged asymmetry with respect to the central axis in a table facet front view. , Each facet except the culet of the pavilion is arranged point-symmetrically with respect to the central axis.

<Embodiment 4 Configuration of the Invention>
According to the invention of this embodiment, in addition to the configuration described in the first to third embodiments, each facet except for the table facet of the crown is arranged asymmetry with respect to the center axis in a table facet front view. , Each facet except for the culet of the pavilion is arranged point-symmetrically with respect to the central axis. A typical diamond is configured such that the facet of the crown is point-symmetric with respect to a central axis passing through the center of the table facet and the culet. The configuration according to the present embodiment does not depend on any one of the configurations of the first to third embodiments, and may be an independent configuration.

As shown in FIG. 9A, when the representative light is emitted from the point face symmetrical crown side facet, the representative light is emitted as compared with the case where the representative light is emitted from the astigmatic crown side facet as shown in FIG. 9B. Although the ratio of superimposition is high and the brightness is the same, the glittering (which can be represented by the number of visible lines and the number of visible points of the representative light) is the latter, that is, the crown-side facet is astigmatically symmetric with respect to the central axis. Are larger (more). If the total value of the luminances is the same, the degree of the aesthetic appearance perceived by the observer increases as the glitter increases (increases).

Furthermore, the pavilion side is point symmetric, while the crown side is non-point symmetric. Since the pavilion side mainly plays a role of substantially totally reflecting light incident from the crown side, the ratio of contribution to the viewer's appreciation is low. On the other hand, diamond cutting requires skilled skills, and it is difficult to cut facets asymmetrically. Therefore, it does not matter whether the function of reflecting the incident light in the diamond is point-symmetric or non-point-symmetric. Therefore, it is more advantageous in manufacturing to make the point-symmetrical one that is easy to cut. The cutting process may be divided into a process assigned to a worker with a high level of skill and a process assigned to a worker with a low level of skill. The former may be used for the operation on the crown side, and the latter may be used for the operation on the pavilion side. Since the point symmetric pavilion process is easier, it is preferable to arrange the pavilion cutting process before the crown cutting process. Also, since the diamond pavilion is cut while observing the balance, it may be conceivable to proceed with the pavilion ahead, such as pavilion → crown → pavilion → crown, in some cases.

<Embodiment 5>
<Embodiment 5 of the Invention>
The invention according to the present embodiment is characterized in that in addition to the features described in the first to fourth embodiments, the number of cut surfaces to be performed in the round cut is specified to be 55 crowns and 88 pavilion total surfaces of 88 surfaces. Features.

<Embodiment 5 of the invention>
FIG. 10 is a diagram illustrating an example of an ideal cut of a round cut diamond according to the present embodiment. As shown in the figure, the round cut diamond according to the present embodiment has the configuration described in any of the first to fourth embodiments, and the table facet (1001) has a nine-sided shape, excluding the girdle facet. The number of facets constituting the crown (1002) is 54 except for the table facet, and the number of facets constituting the pavilion (1003) is 32 without counting the curette as a surface except for the girdle facet, The total number of facets is 88 including the table facets and the girdle facets. It should be noted that even if the curette forms a surface, the emitted light cannot be viewed, so that it is not counted as a surface.

であれば If the number of facets formed on the crown side is 55 and the number of facets formed on the pavilion side is 33, the shape of the facet and the angle of the facet need not be limited. However, it is desirable that light be uniformly reflected in order to make the glitter of the diamond most attractive. Therefore, it is preferable that each facet is regularly arranged. That is, for example, with respect to the crown-side facet, when the table facet is used as a starting point, all facets that are in contact with the sides of the table facet are formed of the same shape, the same size, and the same oblique angle, Facets that are in contact with the table facet only at the vertices have the same shape, the same size, and the same bevel, so that all facets that satisfy the same conditions in relation to the table facet Most desirably, they have the same shape, the same size, and the same oblique angle. Facets that have different conditions in relation to the table facets do not need to have the same shape, the same size, and the same oblique angle. Further, with respect to the pavilion facet, facets that satisfy the same conditions in relation to the culet surface, when starting from the culet surface, are all configured with the same shape, the same size, and the same oblique angle. Is most desirable.

Furthermore, if the cut configuration of the round cut in the present embodiment is expressed by a plane, it is desirable that the configuration is as shown in FIG. As for the facet of the crown, as shown in the upper part of FIG. 10, nine triangular first facets (1004) each having one side of a nine-sided face constituting the table facet, and a table facet. The vertices of the 9-sided shape are their own vertices, and the 9th-sided second facets (1005) that do not come into contact with the table facet in other portions, and the 4-sided shape that contacts only the first facet and one vertex of the first facet 9 of the third facet (1006), 18 of the fourth square facets (1007) having one side of the third facet as one side, one side of a fourth facet and one side of another fourth facet It is composed of nine triangular fifth facets (1008) as its own sides. And, when a straight line is drawn from a certain vertex of the table facet so as to intersect the center axis, the straight line passes through the vertices of all the first to fifth facets. Is an ideal configuration. As an example of such a configuration, a straight line drawn through the central axis at an angle of 20 degrees with respect to a straight line drawn through the central axis from the vertex of the 9-sided facet of the table facet is formed as a table facet. And all the facets of the first to fifth facets are configured to pass through the vertex.

As for the facet of the pavilion, as shown in the diagram at the bottom of FIG. 10, another straight culet starting from a straight line (1009) passing through the culet and having an interval of 22.5 degrees from the straight line as the starting point An auxiliary straight line (1010) passing through is drawn, the auxiliary straight line is divided into three, and the dividing points of the auxiliary line are defined as a first dividing point (1011) and a second dividing point (1012) in order from the one closer to the curette. Draw a first sentence division point and a first connection line (1013) connecting the end point of the straight line serving as the starting point, which is shorter in distance from the first division point, and draw a parallel from the second division point to the first connection line. Is drawn toward a straight line serving as a starting point (1014), and a similar form is repeated in the case where a line starting from an auxiliary line is used as a starting point.

FIG. 11 is a diagram reproducing an experimental result photograph showing light reflection when an irradiation experiment of irradiating a laser to 88 round-cut diamonds in the present embodiment is performed. FIG. 12 is a reproduction of a conventional experimental result photograph showing light reflection in a conventional irradiation experiment of irradiating a laser to 58 round-cut diamonds (where the curette is counted as a surface). As is apparent from a comparison between FIG. 11 and FIG. 12, the number of light beams reflected in FIG. 11 is relatively large. The number of reflected rays is the amount of diamond shine. Therefore, as shown in FIG. 11, it can be said that the round cut diamond of 88 faces, which has a relatively large number of reflected light rays, has more brightness than the cut of 58 faces.

FIG. 15 shows the results of a questionnaire in which the conventional cut diamonds and the diamonds of Embodiments 5 and 6 are shown at the same time, and the order of brightness is 1, 2, and 3 in that order. As shown in the table, when comparing the brightness of the diamond of the fifth embodiment with the diamond of the conventional cut, all the persons who responded to the questionnaire answered that the brightness of the fifth embodiment was strong. Thus, from the viewpoint of the observer, it is recognized that the brightness of the diamond of the fifth embodiment is greater than that of the conventional cut diamond.

FIG. 16 shows the results of a questionnaire in which the favorite designs when the conventional diamond and the diamonds of Embodiments 5 and 6 are simultaneously shown are described as 1, 2, and 3 in the order of preference. As shown in the table, comparing the appearance preference of the diamond of the conventional cut with the diamond of the fifth embodiment, all the respondents to the questionnaire showed that the design of the fifth embodiment had a more outward appearance than the conventional diamond crest. It is recognized that he is judged beautiful.

<Diamond value evaluation criteria>
Here, the diamond value evaluation criteria will be described. The current treatment is that the criteria for attaching a certificate to a diamond are only those that satisfy the so-called 4C standard. 4C is clarity, color, cut, carat weight. Points are set for each stage of these four elements, and the points of each element are summed up to evaluate the value of the entire diamond. Therefore, the value of a diamond is determined by judging each element in combination.

クラ “Clarity” refers to the transparency of diamonds. Transparency is evaluated based on the internal features of natural diamond, called inclusions, and the relatively small number of features on the surface called blemishes. Blemish also includes scratches and chips on the surface of the diamond. In addition to the distinction between clarity features and natural diamonds, no two diamonds have exactly the same inclusions in exactly the same place, so one diamond is identical to a previously identified diamond It can be used as a landmark when judging whether or not it is. The diamonds with the highest ratings have no visible inclusions or blemishes when viewed by a skilled and experienced appraiser at 10x magnification. All other factors determining value are equal, the higher the clarity, the higher the price of diamonds per carat. The evaluation of clarity is determined by comprehensively evaluating the size, number, position, nature, color, and relief (contour, visibility) of inclusions and blemishes. The relative importance of each factor varies from diamond to diamond. For example, it is believed that if the inclusion is skewed to the side of the stone, it will have less impact on clarity than if there is an inclusion of the same size directly below the table. In such a case, it can be said that the position is a determining factor of the evaluation.

"Color" refers to the color of a diamond. Subtle differences in color can have a significant effect on the value of a diamond, and two diamonds of equal clarity, weight, and cut can differ in value only in the color component. Diamonds come in a variety of colors. Colorless to pale yellow and pale brown diamonds are said to be in the normal color range. In the normal color gamut, the closer the diamond is to colorless, the higher the value. In addition, many diamonds reflect visible light called fluorescence when irradiated with ultraviolet light. Fluorescence includes blue, white, yellow, orange and the like. If the fluorescence is too strong, the appearance of the stone may appear cloudy, which is called "oily" and reduces the value of the diamond.

"Cut" is the evaluation of the diamond proportions (shape and finish). The cut is deeply related to the radiance of the diamond. The light that enters the diamond becomes a brilliant diamond due to the excellent refractive index of the diamond and the ideal proportion determined from the refractive index. Unless there are large scratches or inclusions that hinder the light path inside the diamond, a better cut will shine more.

“Carat” is a unit of weight (ct) of a jewel, and indicates the weight of a diamond, not the size. One carat is fixed at 200 grams.

示す As shown in the above table or criteria, among the factors that determine the value of diamond, only the field of cutting can be differentiated by human skill. Therefore, in order to make the diamond more valuable, it is preferable to make a cut that can make the glitter of the diamond more prominent. The 88-face cut in the present embodiment is more brilliant than the conventional 58-face cut, and can further enhance its value as a diamond.

<Embodiment 6>
<Sixth Embodiment Outline of the Invention>
The invention in this embodiment is characterized in that, in addition to the features described in the first to fourth embodiments, the number of cut surfaces to be performed in the round cut is specified as 37 crowns, 26 pavilion, and 63 total surfaces. Features.

<Sixth Embodiment Configuration of the Invention>
FIG. 13 is a diagram illustrating an example of an ideal cut of a round cut diamond in the present embodiment. As shown in the figure, the round cut diamond according to the present embodiment has the configuration described in any one of the first to fourth embodiments, and the table facet (1301) has a nine-sided shape, excluding the girdle facet. The number of facets constituting the crown (1302) is 36 except for the table facet, and the number of facets constituting the pavilion (1303) is 25 except for the girdle facet and counting the curette as a surface, The total number of facets is 63 including the table facet and the girdle facet. If the culet is not counted as a surface, the number is 62.

Also in the land-cut diamond according to the present embodiment, if the number of facets formed in the crown is 37 and the number of facets formed in the pavilion is 25 counting the curette as a surface, the shape of the facet and the angle of the facet Is not limited. Further, the facet or facet satisfying the same condition in relation to the table facet or the culet surface has the same beautiful shape, the same size, and the same oblique angle. Same as cut diamond.

Furthermore, if the cut configuration of the round cut in the present embodiment is expressed by a plane, it is desirable that the configuration is as shown in FIG. As for the facet of the crown, as shown in the upper part of FIG. 13, nine triangular first facets (1304) each having one side of a nine-sided face constituting the table facet and a table facet. Nine vertices are set as the vertices of the self, nine other quadrangular second facets (1305) not in contact with the table facet in other portions, and a third facet (1306) of a triangle having one side of the second facet as one side of itself. And 18). When a straight line is drawn from a certain vertex of the table facet so as to intersect the center axis, the straight line passes through the vertices of all of the first to third facets. Is an ideal configuration. As an example of such a configuration, a straight line drawn through the central axis at an angle of 20 degrees with respect to a straight line drawn through the central axis from the vertex of the 9-sided facet of the table facet is formed as a table facet. And all the facets of the first to third facets are configured to pass through the vertex.

As for the facet of the pavilion, as shown in the figure at the bottom of FIG. 13, another straight culet starting from a straight line (1307) passing through the culet and having an interval of 22.5 degrees from the straight line as the starting point Is drawn, an auxiliary straight line (1308) is drawn, the auxiliary straight line is divided into two, and the auxiliary line is divided into two points (1309). A connecting line (1310) connecting an end point of a straight line serving as a starting point, which is shorter in distance from the division point. , And the same configuration is repeated for a straight line starting from the auxiliary line.

FIG. 14 is a diagram reproducing an experimental result photograph showing the reflection of light when performing an irradiation experiment of irradiating a laser to 63 round-cut diamonds in the present embodiment. FIG. 12 is a diagram showing light reflection when an irradiation experiment in which a laser is applied to 58 round-cut diamonds as described above. As is apparent from a comparison between FIG. 14 and FIG. 12, the number of light beams reflected in FIG. 14 is relatively large. The number of reflected rays is the amount of diamond shine. Therefore, as shown in FIG. 14, it can be said that the 63-round cut diamond, which has a relatively large number of reflected light beams, has more brightness than the 58-plane cut. As described above, in diamonds having the same conditions other than cutting, it is considered that a stronger shine is more valuable, and the 63 face cut in the present embodiment is more brilliant than the conventional 58 face cut. It is possible to further increase the value as a diamond.

As shown in FIG. 15, when comparing the brightness of the diamond of the sixth embodiment with the diamond of the conventional cut, all the persons who answered the questionnaire answered that the brightness of the sixth embodiment was strong. Thus, from the viewpoint of the observer, it is recognized that the brightness of the diamond according to claim 6 is higher than that of the conventional cut diamond.

As shown in FIG. 16, when comparing the apparent preference between the diamond of the conventional cut and the diamond of the sixth embodiment, all of the persons who responded to the questionnaire showed that the design of the sixth embodiment was better than the conventional diamond crest. It is recognized that he is judged to be beautiful in appearance.

<Embodiment 7>
<Seventh Embodiment of the Invention>
The girdle is inclined from the center of the table facet to the center axis passing through the center of the culet surface by 0.1 to 45 degrees outside the crown (however, the angle is limited to an angle smaller than the angle formed by the crown surface with the center axis). The girdle facet is composed of girdle facets, and the total reflection of the light beam incident from the table facet and reflected on the pavilion side facet is reduced by the girdle. This is a method for producing diamond.

<Embodiment 7 Configuration of the Invention>
According to the invention in this embodiment, the girdle is 0.1 degrees or more and 45 degrees outside the crown with respect to a center axis extending from the center of the table facet to the center of the culet surface (however, the angle formed by the crown surface with the center axis is smaller than the angle). The girdle facet is composed of a girdle facet that is inclined below, and the total reflection of the light beam incident from the table facet and reflected by the facet on the pavilion side is reduced by a girdle. Is formed by grinding.

<Embodiment 7 Configuration Description>
The “grinding” is to remove (cut) or / and polish a rough diamond or a diamond that has already been cut, thereby smoothing the removed surface, adjusting the shape of the removed surface, and adjoining. This refers to highlighting the boundaries between deleted surfaces.

Specifically, "cleaving" is a cutting method that uses "cleaving", and "sewing" is cutting using diamond powder inside the rough along the softest hexahedral surface and then the softer dodecahedral surface. Make such a cut. Thereafter, a step of polishing and finishing is performed. It is roughly divided into two steps. The cutting process is being performed more precisely using dedicated instruments. Furthermore, the girdle is determined by bruting, and the maximum width of the finished diamond is determined at this stage. Then saw the table, cut it out, and start the faceting work to finish individual faces from there. After rough faceting, finish polishing is performed. At this stage, the final angle adjustment and the adjustment of the polished surface are performed finely, and the diamond approaches the completion.

Alternatively, old cut diamonds may be re-formed in this case. In this case, the shape of the surface may be adjusted only by removal or polishing only, and the boundary between adjacent removed surfaces may be emphasized. The tool used for the grinding may be a diamond grindstone, a laser (rough cut of a rough stone), or any type of tool that has the ability to remove and polish diamonds.

<Embodiment 8>
<Eighth Embodiment of the Invention>
According to the invention in this embodiment, the girdle is 0.1 degree or more and 45 degrees inward of the crown with respect to a center axis extending from the center of the table facet to the center of the culet surface (however, the angle formed by the pavilion surface and the center axis is smaller than 45 degrees). The girdle facet was constructed with girdle facets that consist of girdle facets that are inclined below, and that increase the total reflection of the light beam incident from the table facet and reflected by the pavilion side facets using a girdle. This is a method for producing round-cut diamonds by grinding diamonds.

<Eighth Embodiment Configuration of the Invention>
According to the invention in this embodiment, the girdle is 0.1 degree or more and 45 degrees inward of the crown with respect to a center axis extending from the center of the table facet to the center of the culet surface (however, the angle formed by the pavilion surface and the center axis is smaller than 45 degrees). The girdle facet was constructed with girdle facets that consist of girdle facets that are inclined below, and that increase the total reflection of the light beam incident from the table facet and reflected by the pavilion side facets using a girdle. A diamond is formed by grinding.

<Embodiment 9>
Embodiment 9 Summary of the Invention
The invention according to the present embodiment is a diamond manufacturing method in which the width of the girdle facet is limited by the ratio to the height difference between the culet face and the table facet, in addition to the features of the seventh or eighth embodiment.

Embodiment 9 Configuration of the Invention
The invention according to this embodiment is characterized in that, in addition to the configuration described in the seventh or eighth embodiment, the width of the girdle facet is 0.2% or more and 10% or less with respect to the height between the curette face and the table facet. Grind a diamond designed with rough diamond or other cuts as follows.

<Embodiment 10>
<Tenth Embodiment Outline of the Invention>
The invention according to the present embodiment is characterized in that, in addition to the features of the seventh to ninth embodiments, each facet except for the table facet in the crown is arranged asymmetry with respect to the central axis in front view of the table facet. It is a method of producing diamond.

<Tenth Embodiment Configuration of the Invention>
According to the invention of this embodiment, in addition to the configuration described in the seventh or ninth embodiment, each facet other than the table facet of the crown is arranged asymptotically with respect to the central axis in front view of the table facet. Grind a rough diamond or other designed diamond as designed.

<Embodiment 11>
<Eleventh Embodiment Outline of the Invention>
The invention according to the present embodiment is characterized in that, in addition to the features described in the seventh to tenth embodiments, the number of cut surfaces to be performed in the round cut is 55 for the crown and 88 for the total number of pavilion 33 surfaces. It is a manufacturing method.

<Eleventh Embodiment Configuration of the Invention>
The configuration of the present invention according to the present embodiment is the same as the configuration according to any one of the seventh to tenth embodiments, except that the table facet is a octagon and the number of facets constituting the crown excluding the girdle facet is a table. Except for the facets, there are 54 faces, and the number of facets constituting the pavilion is 32 without counting the curette as a face except for the girdle facets, and the total number of facets is 88 including the table facets and the girdle facets. As described above, the diamond is designed by grinding a rough diamond or other cut.

<Embodiment 12>
<Twelfth Embodiment Outline of the Invention>
The invention according to the present embodiment is characterized in that, in addition to the features described in the seventh to tenth embodiments, the number of cut surfaces to be cut in the round cut is 37 for the crown, 26 for the pavilion, and 63 for the total number of surfaces. It is a manufacturing method.

<Twelfth Embodiment Structure of the Invention>
The invention according to the present embodiment is characterized in that, in addition to the features described in any one of the seventh to tenth embodiments, the table facet is a octagon, and the number of facets constituting the crown excluding the girdle facet is the same as the table facet. Excluding the girdle facet, the number of facets constituting the pavilion is 25 including the curette as a surface, and the total number of facets is 63, including the table facet and the girdle facet. Grind and form diamonds designed with rough or other cuts.

0101 Table facet 0102 Crown 0103 Pavilion 0104 Crown facet 0105 Girdle facet 0106 Curette (face)
0107 Pavilion Side Facet 0108 Crown Lower Edge

Claims

The girdle is 0.1 degrees or more and 45 degrees outside the lowermost edge of the crown with respect to the center axis passing from the center of the table facet to the center of the culet plane (however, it is limited to an angle smaller than the angle formed by the crown surface with the center axis). A round cut diamond having a girdle facet which is constituted by a girdle facet which is inclined in the following and has a girdle for reducing the total reflection of a light beam incident from the table facet and reflected by the facet on the pavilion side.
The girdle is 0.1 ° or more and 45 ° inside the lowermost edge of the crown with respect to the center axis passing from the center of the table facet to the center of the culet plane (however, limited to an angle smaller than the angle formed by the pavilion plane with the center axis) A round-cut diamond having a girdle facet which is constituted by an inclined girdle facet and has a girdle that increases the total reflection of a light beam incident from the table facet and reflected by the pavilion facet by a girdle.
The round diamond according to claim 1 or 2, wherein the width of the girdle facet is 0.2% or more and 10% or less with respect to the height between the curette face and the table facet.
Each facet except for the table facet of the crown is arranged asymmetrically with respect to the central axis in a front view of the table facet, and each facet except for the culet of the pavilion is arranged with point symmetry with respect to the central axis. The round cut diamond according to any one of claims 1 to 3.
The table facets are 9-sided, the number of facets constituting the crown excluding the girdle facets is 54 except for the table facets, and the number of facets constituting the pavilion is excluding the girdle facets and the curette as a surface. The round cut diamond according to any one of claims 1 to 4, wherein the number is 32 without counting, and the total number of facets is 88 including a table facet and a girdle facet.
The table facets are 9-sided, the number of facets constituting the crown excluding the girdle facets is 36 excluding the table facets, and the number of facets constituting the pavilion is excluding the girdle facets and the curette as a surface. The round-cut diamond according to any one of claims 1 to 4, wherein the number is 25 and the total number of facets is 63 including a table facet and a girdle facet.
The girdle is inclined from the center of the table facet to the center axis passing through the center of the culet surface by 0.1 to 45 degrees outside the crown (however, the angle is limited to an angle smaller than the angle formed by the crown surface with the center axis). The girdle facet is composed of girdle facets, and the total reflection of the light beam incident from the table facet and reflected on the pavilion side facet is reduced by the girdle. Diamond manufacturing method.
The girdle is tilted from the center of the table facet to the center axis passing through the center of the culet plane at an angle of 0.1 to 45 degrees inside the crown (however, limited to an angle smaller than the angle between the pavilion surface and the center axis). The girdle facet is constructed by girdle facets, and the total reflection of the light beam incident from the table facet and reflected by the pavilion side facet is increased by the girdle. Diamond manufacturing method.
The girdle facet is formed by grinding a rough diamond or another diamond designed so that the width of the girdle facet is 0.2% or more and 10% or less of the height between the curette face and the table facet. A method for producing a round-cut diamond according to claim 7 or claim 8.
8. Each of the facets except the table facet of the crown is formed by grinding a rough diamond or another diamond designed so as to be arranged asymmetry with respect to the central axis in a front view of the table facet. A method for producing a round cut diamond according to any one of claims 1 to 9.
The table facets are 9-sided, the number of facets constituting the crown excluding the girdle facets is 54 except for the table facets, and the number of facets constituting the pavilion is excluding the girdle facets and the curette as a surface. 11. The diamond formed by grinding a rough diamond or another cut so that the number of facets is 32 without counting and the total number of facets is 88 including table facets and girdle facets. A method for producing a round-cut diamond according to any one of the preceding claims.
The table facets are 9-sided, the number of facets constituting the crown excluding the girdle facets is 36 excluding the table facets, and the number of facets constituting the pavilion is excluding the girdle facets and the curette as a surface. 11. The diamond formed by grinding a rough diamond or another cut so that the number of facets is 25 and the total number of facets is 63 including a table facet and a girdle facet. A method for producing a round-cut diamond according to item 1.