US20170202319A1

US20170202319A1 - Jewel

Info

Publication number: US20170202319A1
Application number: US15/308,087
Authority: US
Inventors: Hiroyuki Koganei; Tsubasa Koganei
Original assignee: Tasuko Co Ltd
Current assignee: Tasuko Co Ltd
Priority date: 2014-05-01
Filing date: 2015-04-30
Publication date: 2017-07-20
Also published as: JP2015211728A; WO2015166989A1; JP5788562B1

Abstract

[Problem] The purpose of the present invention is to provide a jewel on which cuts with excellent symmetry are made, such cuts having originality, exceling aesthetically, and being novel. [Solution] A diamond (1), serving as a jewel, is cut so as to have a crown (3) provided with a table (2), and a pavilion (5) provided with a culet (4). By creatively modifying the shape and disposition of a main facet (8) formed in the pavilion (5), the diamond (1) is configured so that a heart pattern can be made to appear when the diamond (1) is viewed from the table (2) side.

Description

BACKGROUND OF INVENTION

1. Field of the Invention
The present invention relates to a jewel having cuts formed thereon, the cuts having originality and excelling aesthetically.
2. Description of the Related Art
Jewelry, especially diamond, having a cut called “round brilliant cut” formed thereon has been known to the public. FIG. 1 depicts a diamond 1 having the “round brilliant cut” formed thereon. FIG. 1A is a plan view of the diamond 1, FIG. 1B is a bottom plan view of the diamond 1, and FIG. 1C is a side view of the diamond 1. As shown in FIG. 1, the diamond 1 includes a crown 3 having a table (upper plane) 2, a pavilion 5 having a curette 4, and a girdle 6, which is cut into a round shape between the crown 3 and the pavilion 5.
In general, on a jewel cut into a cut pattern, a curette is formed as a tiny facet that prevents the chipping of the top end of a pavilion. In this specification and claims pertaining to the present invention, however, the top end of a pavilion not formed as a facet but as a pointed apex (pointed curette), as shown in FIG. 1, is also described as a curette.
Some diamonds 1 having the above cut formed thereon are particularly excellent in cut symmetry. It is known that when observing such a diamond 1 from above (from the table 2 side shown in FIG. 1A), one can see eight arrows 7, as shown in FIG. 2. The arrows 7 are visible to the naked eyes, and can be seen more clearly using a gemological microscope descried in Japanese Patent Application Laid-Open Publication No. 06-174648 (patent document 1), Japanese Unexamined Patent Application Publication No. 2010-201043 (patent document 2), etc.
Since the arrows 7 can be seen only on the jewel with particularly excellent cut symmetry, the visibility of the arrows 7 is widely used as a means for proving the high quality of a jewel. Meanwhile, the round brilliant cut is widely recognized as one of completed jewelry cut techniques. Hence the visibility of the eight arrows 7 is well known today as a feature of a quality jewel.
Various jewels showing patterns different from the eight arrows 7 have been proposed. For example, patent document 2 discloses a diamond showing a heart pattern as well as arrows, as visually recognizable patterns, and Japanese Unexamined Patent Application Publication No. 2004-299370 (patent document 3) discloses a diamond showing not eight but ten arrows as a visually recognizable pattern. The inventor of the present invention proposed a jewel showing a cross pattern as a visually recognizable pattern, disclosing the jewel in Japanese Unexamined Patent Application Publication No. 2008-541800 (patent document 4).
Under such circumstances, the inventor has studied diligently on how to fabricate a novel diamond having cuts with excellent symmetry formed thereon, the diamond having originality and excelling aesthetically. The study has led to a piece of knowledge that a totally new diamond having the above features can be fabricated by modifying the shape and disposition of main facets formed on the pavilion, thus allowing the inventor to bring about the present invention. The inventor has confirmed that the invention apply also to jewels other than diamond.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a jewel having novel cuts with excellent symmetry formed thereon, such cuts having originality and excelling aesthetically.
In order to achieve the object of the present invention, a jewel according to the present invention includes a crown having a table, a pavilion having a curette, and a girdle formed between the crown and the pavilion. The pavilion has four or more main facets all or some of which are of triangles, quadrangles, or polygons each having six or more angles. All the main facets are formed such that in each main facet, the distance between the curette and the apex of an angle of the main facet, the angle being closest to the girdle, is less than 90% of the distance between the curette and the girdle. The main facets are arranged such that they are line symmetry with respect to an axis of symmetry which is at least one of lines passing through the curette to bisect the pavilion.
A jewel according to the present invention includes a crown having a table, a pavilion having a curette, and a girdle formed between the crown and the pavilion. The pavilion has six or more main facets all or some of which are of polygons each having three or more angles. All the main facets are formed such that in each main facet, the distance between the curette and the apex of an angle of the main facet, the angle being closet to the girdle, is less than 90% of the distance between the curette and the girdle. The main facets are arranged such that they are line symmetry with respect to an axis of symmetry which is at least one of lines passing through the curette to bisect the pavilion.
A jewel according to the present invention includes a crown having a table, a pavilion having a curette, and a girdle formed between the crown and the pavilion. The pavilion has eight or more main facets all or some of which are of quadrangles each having interior angles all different from each other or of polygons each having five or more interior angels all different from each other. All the main facets are formed such that in each main facet, the distance between the curette and the apex of an angle of the main facet, the angle being closest to the girdle, is less than 90% of the distance between the curette and the girdle. The main facets are arranged such that they are line symmetry with respect to an axis of symmetry which is at least one of lines passing through the curette to bisect the pavilion.
A jewel according to the present invention includes a crown having a table, a pavilion having a curette, and a girdle formed between the crown and the pavilion. The pavilion has eight main facets made up of four first main facets that are of pentagons each having interior angels all different from each other and four second main facets that are of pentagons line symmetrical to the pentagons serving as the first main facets. The first main facets and the second main facets are arranged alternately on the pavilion. Each of the pentagons serving as the first main facets and the second main surfaces is formed such that the distance between the curette and the apex of an angle of the pentagon, the angle being closest to the girdle, is less than 90% of the distance between the curette and the girdle.
A jewel according to the present invention includes a crown having a table, a pavilion having a curette, and a girdle formed between the crown and the pavilion. The pavilion has ten main facets made up of five first main facets that are of pentagons each having interior angels all different from each other and five second main facets that are of pentagons line symmetrical to the pentagons serving as the first main facets. The first main facets and the second main facets are arranged alternately on the pavilion. Each of the pentagons serving as the first main facets and the second main surfaces is formed such that the distance between the curette and the apex of an angle of the pentagon, the angle being closest to the girdle, is less than 90% of the distance between the curette and the girdle.
The jewel according to the present invention is a diamond.
The present invention offers a jewel having novel cuts with excellent symmetry formed thereon, such cuts having originality and excelling aesthetically.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows external views of a diamond having a round brilliant cut formed thereon;

FIG. 2 is a diagram showing a state of appearance of arrows 7;

FIG. 3 is a diagram showing a state of appearance of the arrows 7;

FIG. 4 is a diagram showing reflected light images R created by main facets 8;

FIG. 5 is a diagram showing a path of light passing through a diamond 1;

FIG. 6 is a diagram showing the principle of appearance of the arrows 7;

FIG. 7 is a diagram showing the principle of appearance of the arrows 7;

FIG. 8 shows external diagrams of a diamond 1 according to an embodiment of the present invention;

FIG. 9 depicts a photograph of a heart pattern;

FIG. 10 is a diagram showing a state of appearance of a hear pattern 13;

FIG. 11 is a diagram showing the principle of appearance of the hear pattern 13;

FIG. 12 is a diagram showing the principle of appearance of the hear pattern 13;

FIG. 13 is a diagram showing the principle of appearance of the hear pattern 13;

FIG. 14 is a diagram showing the principle of appearance of the hear pattern 13;

FIG. 15 is a diagram showing the principle of appearance of the hear pattern 13;

FIG. 16 is a diagram of a pavilion 5 for causing a four-leaf clover pattern to appear;

FIG. 17 is a diagram showing a state of appearance of the four-leaf clover pattern;

FIG. 18 depicts a photograph of the four-leaf clover pattern;

FIG. 19 is a diagram of the pavilion 5 for causing a peach blossom pattern to appear;

FIG. 20 is a diagram showing a state of appearance of the peach blossom pattern;

FIG. 21 depicts a photograph of the peach blossom pattern;

FIG. 22 is a diagram of the pavilion 5 for causing a cherry blossom pattern to appear;

FIG. 23 is a diagram showing a state of appearance of the cherry blossom pattern;

FIG. 24 depicts a photograph of the cherry blossom pattern;

FIG. 25 is a diagram of the pavilion 5 for causing a butterfly pattern to appear;

FIG. 26 is a diagram showing a state of appearance of the butterfly pattern;

FIG. 27 is a diagram of the pavilion 5 for causing a pattern of the House of Takeda's family crest (takeda-bishi) to appear;

FIG. 28 is a diagram showing a state of appearance of the pattern of the House of Takeda's family crest (takeda-bishi);

FIG. 29 is a diagram of the pavilion 5 for causing a narcissus blossom pattern to appear;

FIG. 30 is a diagram showing a state of appearance of the narcissus blossom pattern;

FIG. 31 shows diagrams of the diamond 1 having a square girdle 6;

FIG. 32 shows diagrams of the diamond 1 having an elliptic girdle 6; and

FIG. 33 depicts the principle of appearance of the reflected light images R in a four-leaf clover pattern.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of a jewel according to the present invention will hereinafter be described. It is confirmed that understanding the principle of appearance of arrows in a diamond having a conventional round brilliant cut formed thereon, particularly, understanding the principle of appearance of the shaft portions of the arrows will be a great help in understanding the present invention. For this reason, the principle of appearance of the shaft portions of the arrows will first be described.
FIG. 1 depicts a diamond 1 having the round brilliant cut formed thereon. FIG. 1A is a plan view of the diamond 1, FIG. 1B is a bottom plan view of the diamond 1, and FIG. 1C is a side view of the diamond 1. As shown in FIG. 1, the diamond 1 includes a crown 3 having a table (upper plane) 2, a pavilion 5 having a curette 4, and a girdle 6 cut into a round shape between the crown 3 and the pavilion 5. In FIG. 1B, 8 denotes eight main facets formed on the pavilion 5, and 9 denotes 16 lower girdle facets formed on the pavilion 5.
FIG. 2 depicts a state of appearance of eight arrows 7 in a case where the diamond 1 is observed from above (table 2 side shown in FIG. 1A). Each arrow 7 is composed of a shaft portion 7 a and an arrowhead portion 7 b. As shown in FIG. 2, the shaft portions 7 a are visually recognized inside the table 2. In the following description of the principle of appearance of the shaft portions 7 a, the vicinity of the bases of the arrows 7, i.e., the vicinity of the center of the diamond 1, which is rendered invisible in the end by light reflected on the diamond 1, will be treated, for convenience, as a visually recognizable pattern, as shown in FIG. 3.
The shaft portions 7 a visually recognized inside the table 2 are created by reflected light images R on the main facets 8, as shown in FIG. 4. The shape of the arrowhead portions 7 b of FIG. 3 is different from the shape of the corresponding portions of the reflected light images R of FIG. 4. This is because that the arrowhead portions 7 b are created by reflected light including a portion of reflected light (not depicted) not making up the reflected light images R. Describing a portion of reflected light not making up the reflected light images R is considered to be unnecessary, and is therefore omitted.
The reflected light images R on the main facets 8 are created basically by the following process. As shown in FIG. 5, light L falls onto a facet 10 on the crown 3 of the diamond 1 and travels toward its interior. Being affected by the inclination of the facet 10 and the refractive index of the diamond 1, light L is reflected consecutively at a first reflection point 11 and a second reflection point 12. Reflected light L then travels outward from inside the table 2 to come out of the diamond 1.
FIG. 6 depicts the above reflection of light occurring twice on the pavilion 5. As shown in FIG. 6, light reflected on a main facet 8 a, where the first reflection point 11 is present, is then reflected on a main facet 8 b, which is opposite to the main facet 8 a with respect to the curette 4 and where the second reflection point 12 is present.
The main facet 8 a and the main facet 8 b face each other in their slant positions. This causes a reflected light image R on the main facet 8 b to contract mainly in its longitudinal direction (horizontal direction in FIG. 6), as shown in FIG. 6. As a result, the reflected light image R becomes smaller in shape than the main facet 8 b.
The light reflection process as described above occurs on all of the eight main facets 8, as shown in FIG. 7. When the reflected light images R created in such a manner are observed from above the diamond 1, the shaft portions 7 a of the eight arrows 7 are visually recognized inside the table 2. This is the principle of appearance of the shaft portions 7 a of the arrows 7 on the diamond having the conventional round brilliant cut formed thereon.
An embodiment of the present invention will then be described. FIG. 8 depicts a diamond 1 provided as a jewel according to the present invention. FIG. 1A is a plan view of the diamond 1, and FIG. 1B is a bottom plan view of the diamond 1. Similar to the diamond having the conventional round brilliant cut formed thereon, the diamond 1 of this embodiment is cut in such a way as to include the crown 3 having the table 2 and the pavilion 5 having the curette 4. This diamond 1 includes also the girdle cut into a round shape (not depicted) between the crown 3 and the pavilion 5, as the diamond having the round brilliant cut does.
As shown in FIG. 8B, modifying the shape and disposition of the main facets 8 formed on the pavilion 5 allows the diamond 1 of this embodiment to cause a pattern different from a conventional arrow pattern to appear. FIG. 9 depicts a photograph of the diamond 1 of this embodiment that is taken from above the diamond 1 (table 2 side shown in FIG. 8A) using a gemological microscope. A pattern visually recognized on the diamond 1 of FIG. 8 imitates a heart shape. The principle of appearance of such a heart pattern will hereinafter be described.
FIG. 10 depicts a state of appearance of a heart pattern 13 in a case where the diamond 1 is observed from above. As shown in FIG. 10, the heart pattern 13 is visually recognized inside the table 2.
The heart pattern 13 visually recognized inside the table 2 is created by the reflected light images R on the main facets 8 formed on the pavilion 5, as shown in FIG. 11. The reflected light images R are created basically by the following process. As shown in FIG. 5, light L falls onto the facet 10 on the crown 3 of the diamond 1 and travels toward its interior. Being affected by the inclination of the facet 10 and the refractive index of the diamond 1, light L is reflected consecutively at the first reflection point 11 and the second reflection point 12. Reflected light L then travels outward through the table 2 to come out of the diamond 1.
FIG. 12 depicts the above reflection of light occurring twice on the pavilion 5. As shown in FIG. 12, light reflected on the main facet 8 a, where the first reflection point 11 is present, is then reflected on the main facet 8 b, which is opposite to the main facet 8 a with respect to the curette 4 and where the second reflection point 12 is present.
The main facet 8 a and the main facet 8 b face each other in their slant positions. This causes a reflected light image R on the main facet 8 b to contract mainly in its longitudinal direction (horizontal direction in FIG. 12), as shown in FIG. 12. As a result, the reflected light image R becomes smaller in shape than the main facet 8 b.
The light reflection process as described above occurs on each of the main facets 8 a and 8 b different in size and shape from each other, as shown in FIGS. 13 to 15. When all the reflected light images R created in such a manner are observed from above the diamond 1, the heart pattern 13 shown in FIG. 10 is visually recognized. According to the above described principle, the diamond 1 of this embodiment causes the heart pattern 13 to appear.
In the embodiment described above, the shape and disposition of facets on the crown 3 are specified (see FIG. 8A). However, according to the present invention, what pattern is to appear is determined by the shape and disposition of the main facets 8. The shape and disposition of the facets on the crown 3 are therefore not limited to specific shape and disposition. If at least the table 2 and the facets with the same inclination as the conventional one (e.g., inclination of 31 degree to 36 degrees for the case of diamond) are formed on the crown 3, such a crown 3 is considered to be applicable.
For example, by forming the main facets 8 on the pavilion 5 in such a manner as shown in FIG. 16, a pattern imitating a four-leave clover, as shown in FIG. 17, is caused to appear, which is visually recognized when the diamond is seen from the table 2 side. FIG. 18 depicts a photograph of this four-leave clover pattern that is taken from the table 2 side using a gemological microscope. For reference, the principle of appearance of the reflected light images R making up the four-leave clover pattern is indicated simply in FIGS. 33A and 33B.
By forming the main facets 8 on the pavilion 5 in such a manner as shown in FIG. 19, a pattern imitating a peach blossom, as shown in FIG. 20, is caused to appear, which is visually recognized when the diamond is seen from the table 2 side. FIG. 21 depicts a photograph of this peach blossom pattern that is taken from the table 2 side using a gemological microscope.
By forming the main facets 8 on the pavilion 5 in such a manner as shown in FIG. 22, a pattern imitating a cherry blossom, as shown in FIG. 23, is caused to appear, which is visually recognized when the diamond is seen from the table 2 side. FIG. 24 depicts a photograph of this cherry blossom pattern that is taken from the table 2 side using a gemological microscope.
By forming the main facets 8 on the pavilion 5 in such a manner as shown in FIG. 25, a pattern imitating a butterfly, as shown in FIG. 26, is caused to appear, which is visually recognized when the diamond is seen from the table 2 side. In FIG. 26, lines on the crown 2 are not depicted.
By forming the main facets 8 on the pavilion 5 in such a manner as shown in FIG. 27, a pattern imitating the House of Takeda's family crest (takeda-bishi), as shown in FIG. 28, is caused to appear, which is visually recognized when the diamond is seen from the table 2 side. In FIG. 28, lines on the crown 2 are not depicted.
By forming the main facets 8 on the pavilion 5 in such a manner as shown in FIG. 29, a pattern imitating a narcissus blossom, as shown in FIG. 30, is caused to appear, which is visually recognized when the diamond is seen from the table 2 side. In FIG. 30, lines on the crown 2 are not depicted.
In each of the above examples, the main facets 8 are formed in a manner different from a manner in which the main facets of the diamond having the conventional round brilliant cut are formed. Specifically, the main facets 8 in each example do not extend up to a position in contact with the girdle. The main facets 8 are formed in this manner because if the main facets 8 extend up to the position in contact with the girdle, the front ends of reflected light images R that are closer to the girdle are concealed by the facets on the crown 3 when the reflected light images R are seen from the table side, in which case an overall view of the reflected light images R cannot be seen inside the table. For this reason, in each of the above examples, every main facet 8 is formed such that the distance between the curette 4 and the apex of an angle of the main facet 8 (e.g., apex 8P of FIG. 8B), the angle being closest to the girdle 6, is less than 90% of the distance between the curette 4 and the girdle 6.
In each of the above examples, the diamond serves as a jewel. It is therefore preferable that the inclination of the facets on the crown be within a range of 31 degrees to 36 degrees against the plane making up the table 2, as the inclination of the same of the diamond having the round brilliant cut is. It is also preferable that the inclination of the facets 8 on the pavilion 5 be within a range of 39 degrees to 42 degrees. This is because of an empirically confirmed fact that determining the inclinations of the facets on the crown and the main facets 8 to be within these angle ranges offers a greater amount of reflected light coming out of the table 2, thus offering a diamond with more brilliance.
It is also preferable in each of the above examples that the inclination of facets other than the main facets 8, the facets being present on the pavilion 5 and located closer to the girdle than the main facets 8, be larger than the inclination of the main facets 8 by 0.5 degrees to 3.0 degrees. This is because that if an inclination difference between the other facets and the main facets 8 is smaller than 0.5 degrees, the boundaries between the main facets 8 and the other facets become unclear, which makes creation of clear reflected light images R impossible. The inclination difference larger than 3.0 degrees, on the other hand, leads to the elongated shape of the diamond as a whole, in which case the beauty of the diamond's appearance is impaired.
In each of the above examples, the diamond serves as a jewel. Obviously, the present invention applies also to jewelry other than diamond. In such a case, the inclination of the facets on the crown and the inclination of the facets on the pavilion including the main facets should be adjusted properly according to the inherent refractive index of a jewel to be used.
It is also preferable in each of the above examples that the size of the table be 40% to 70% of the diameter of the diamond 1, i.e., the diameter of the girdle so that the whole of the reflected light images R on the main facets 8 can be visually recognized inside the table 2. A part of an appeared pattern may become invisible near its center, i.e., near the center of the table 2 because of the limited size of the table 2, light reflection on the diamond 1, etc. The present invention, however, sees no particular problem with such a case for the reason that such a part near the center of the pattern is tiny or is regarded as a part of the appeared pattern itself, which means that the invisibility of the part does not have a particular effect on the aesthetic value of the appeared pattern. It is obvious from the viewpoint of the balanced form of the diamond 1 as a whole that the center of the plane of the table 2 should preferably match an axis passing through the center of the curette 4.
In the above embodiment, the jewel having the girdle cut into a round shape is described. According to the present invention, not only the jewel having the girdle cut into a round shape but also a jewel having the girdle cut into such a non-round shape as quadrangle and ellipse is capable of causing a pattern to appear. This is because that according to the present invention, what pattern is to appear is determined by the shape and disposition of the main facets 8.
For example, as shown in FIG. 31, even if the girdle 6 of the diamond 1 is quadrangular, the heart pattern of FIG. 8 appears inside the table 2 when the shape and disposition of the main facets 8 are the same as those of the diamond 1 that causes the heart pattern to appear. As shown in FIG. 32, even if the girdle 6 of the diamond 1 is elliptic, the heart pattern of FIG. 8 appears inside the table 2 when the shape and disposition of the main facets 8 are the same as those of the diamond 1 that causes the heart pattern to appear.
The above features of the present invention can be summarized as follows.
The jewel according to the present invention includes the crown having the table, the pavilion having the curette, and the girdle formed between the crown and the pavilion.
The jewel according to the present invention includes four or more main facets formed on the pavilion. According to the present invention, the main facets are facets that produce reflected light images for causing a desired pattern to appear. The main facets are present on the pavilion and are of polygons (triangles, etc.) each having three or more angles.
Basically, each of the main facets of the present invention has one end in contact with the curette. However, in the cases of the peach blossom pattern of FIG. 19 and the narcissus blossom pattern of FIG. 29, subfacets 14 with tiny cut lines are formed in contact with the curette 4. In these exceptional cases, one end of each of the main facets 8 is not in contact with the curette 4 because of the presence of the subfacets 14. Nevertheless, in these cases, the main facets serve as the facets that produce the reflected light images for causing the peach blossom pattern or narcissus blossom pattern to appear.
When the subfacets 14 are present on the pavilion 5 as in the above case, it is preferable that the inclination of the subfacets 14 be smaller than that of the main facets 8 by 2 degrees to 4 degrees. This is because that the subfacets 14 with the inclination smaller than that of the main facets 8 by 2 degrees to 4 degrees prevents light reflected on the subfacets 14 from entering the reflected light images R, allowing the main facets 8 to produce the reflected light images R with enhanced clearness.
All the main facets of the present invention are formed such that in each main facet, the distance between the curette and the apex of an angle of the main facet, the angle being closest to the girdle, is less than 90% of the distance between the curette and the girdle. As described above, the main facets are formed in this manner because if the main facets extend up to the position of the girdle, the front ends of reflected light images R that are closer to the girdle are concealed by the facets on the crown when the reflected light images R are seen from the table side, in which case an overall view of the reflected light images R cannot be visually recognized.
The main facets of the present invention are arranged such that they are line symmetry with respect to an axis of symmetry which is at least one of lines passing through the curette to bisect the pavilion. This is because of a confirmed fact that unless at least one axis of symmetry is present, a meaningful pattern imitating something and excelling aesthetically cannot be caused to appear.
The jewel of the present invention may be defined as a jewel having the following feature.
A jewel comprising:
a crown having a table;
a pavilion having a curette; and
a girdle formed between the crown and the pavilion, wherein the pavilion has six or more main facets all or some of which are of polygons each having three or more angles, wherein all the main facets are formed such that in each main facet, the distance between the curette and the apex of an angle of the main facet, the angle being closest to the girdle, is less than 90% of the distance between the curette and the girdle, and wherein the main facets are arranged such that they are line symmetry with respect to an axis of symmetry which is at least one of lines passing through the curette to bisect the pavilion.
The jewel of the present invention may also be defined as a jewel having the following feature.
A jewel comprising:
a crown having a table;
a pavilion having a curette; and
a girdle formed between the crown and the pavilion, wherein the pavilion has eight or more main facets all or some of which are of quadrangles each having interior angles all different from each other or of polygons each having five or more interior angels all different from each other, wherein all the main facets are formed such that in each main facet, the distance between the curette and the apex of an angle of the main facet, the angle being closest to the girdle, is less than 90% of the distance between the curette and the girdle, and wherein the main facets are arranged such that they are line symmetry with respect to an axis of symmetry which is at least one of lines passing through the curette to bisect the pavilion.
The jewel capable of causing the pattern imitating the four-leave clover to appear, which is included in the above examples, may be defined as a jewel having the following features.
A jewel comprising:
a crown having a table;
a pavilion having a curette; and
a girdle formed between the crown and the pavilion, wherein the pavilion has ten main facets made up of five first main facets that are of pentagons each having interior angels all different from each other and five second main facets that are of pentagons line symmetrical to the pentagons serving as the first main facets, wherein the first main facets and the second main facets are arranged alternately on the pavilion, and wherein each of the pentagons serving as the first main facets and the second main surfaces is formed such that the distance between the curette and the apex of an angle of the pentagon, the angle being closest to the girdle, is less than 90% of the distance between the curette and the girdle.
The jewel capable of causing the pattern imitating the peach blossom to appear and the jewel capable of causing the pattern imitating the cherry blossom to appear, which jewels are included in the above examples, may each be defined as a jewel having the following features.
A jewel comprising:
a crown having a table;
a pavilion having a curette; and
a girdle formed between the crown and the pavilion, wherein the pavilion has ten main facets made up of five first main facets that are of pentagons each having interior angels all different from each other and five second main facets that are of pentagons line symmetrical to the pentagons serving as the first main facets, wherein the first main facets and the second main facets are arranged alternately on the pavilion, and wherein each of the pentagons serving as the first main facets and the second main surfaces is formed such that the distance between the curette and the apex of an angle of the pentagon, the angle being closest to the girdle, is less than 90% of the distance between the curette and the girdle.
As described above, the present invention offers a jewel having novel cuts with excellent symmetry formed thereon, such cuts having originality and excelling aesthetically.

EXPLANATION OF LETTERS AND NUMERALS

- 1 External view of a diamond having a round brilliant cut formed thereon
- 2 Table
- 3 Crown
- 4 Curette
- 5 Pavilion
- 6 Girdle
- 7 Arrow
- 7 a Shaft portion of the arrow 7
- 7 b Arrowhead portion of the arrow 7
- 8 Main facet
- 8 a Main facet where a first reflection point 11 is present
- 8 b Main facet where a second reflection point 12 is present
- 8 p Apex of an angle of the main facet 8, the angle being closest to the girdle 6
- 9 Lower girdle facet
- 10 Facet
- 11 First reflection point
- 12 Second reflection point
- 13 Heart pattern
- 14 Subfacet
- 15 Incoming light
- 16 Reflected light image

Claims

1. A jewel comprising:

a crown having a table;

a pavilion having a curette; and

a girdle formed into a round cut between the crown and the pavilion, wherein the pavilion has eight or more main facets all or some of which are of quadrangles each having interior angles all different from each other or of polygons each having five or more interior angles all different from each other, wherein all the main facets are formed such that in each main facet, a distance between the curette and an apex of an angle of the main facet, the angle being closest to the girdle, is less than 90% of the distance between the curette and the girdle, and wherein the main facets are arranged such that they are line symmetry with respect to an axis of symmetry which is at least one of lines passing through the curette to bisect the pavilion.

2. A jewel comprising:

a crown having a table;

a pavilion having a curette; and

a girdle formed between the crown and the pavilion, wherein the pavilion has eight main facets made up of four first main facets that are of pentagons each having interior angels all different from each other and four second main facets that are of pentagons line symmetrical to the pentagons serving as the first main facets, wherein the first main facets and the second main facets are arranged alternately on the pavilion, and wherein each of the pentagons serving as the first main facets and the second main surfaces is formed such that a distance between the curette and an apex of an angle of the pentagon, the angle being closest to the girdle, is less than 90% of the distance between the curette and the girdle.

3. A jewel comprising:

a crown having a table;

a pavilion having a curette; and

a girdle formed between the crown and the pavilion, wherein the pavilion has ten main facets made up of five first main facets that are of pentagons each having interior angels all different from each other and five second main facets that are of pentagons line symmetrical to the pentagons serving as the first main facets, wherein the first main facets and the second main facets are arranged alternately on the pavilion, and wherein each of the pentagons serving as the first main facets and the second main surfaces is formed such that a distance between the curette and an apex of an angle of the pentagon, the angle being closest to the girdle, is less than 90% of the distance between the curette and the girdle.

4. The jewel according to claim 1, wherein the jewel is a diamond.

5. The jewel according to claim 2, wherein the jewel is a diamond.

6. The jewel according to claim 3, wherein the jewel is a diamond.