Cut stone and its manufacturing method

Abstract

To provide cut stones and methods for manufacturing them. [Solution] The present invention relates to a cut stone and a method for manufacturing the same, and more particularly to a cut stone or semi-precious stone having a crown with a table at the top, a pavilion, and a girdle at the boundary between the crown and the pavilion, the cut angle of the facet surface P2 being 35° to 45°, the cut angle of the facet surface P4 being 25° to 35°, and the ratio of the total height (H) to the diameter or length (L) of the cut stone or semi-precious stone being less than 0.50, preferably 0.50 to 0.40, and more specifically about 0.43.

Description

Technical Field

[0001] The present invention relates to the field of cutting precious and semi-precious stones such as diamonds, and more particularly to the field of use for timepieces or jewelry.

Background Art

[0002] In high-class timepieces, hard materials such as jasper, mother-of-pearl, onyx, or precious or semi-precious stones, particularly diamonds, are generally attached to the dial or other exterior parts of timepieces such as wristwatches or watch clasps, or to jewelry.

[0003] In order to obtain a specific aesthetic effect, it is possible to devise a unique shape including intarsia. However, these hard materials, particularly cut precious or semi-precious stones, need to be arranged in a perfect geometric shape.

[0004] In fact, optimally incorporating these hard materials (particularly cut precious or semi-precious stones) as components of exterior parts is a factor that determines the quality and finish level of timepieces or jewelry, and defines the manufacturer's brand image.

[0005] When viewed in cross-section, cut precious or semi-precious stones have an upper part called the crown and a lower part called the pavilion.

[0006] The upper part of the crown forms a table, the crown is separated from the pavilion by a girdle, and the lower end of the pavilion forms the culet of the cut precious or semi-precious stone.

[0007] Both the pavilion and the crown have a plurality of facets on the side, and depending on their shape, the facets are called star facets, half facets, bezel facets or table corners in the crown, and pavilion or half facets in the pavilion.

[0008] The cutting of precious or semi-precious stones, especially diamonds, is both an art and a science. Certificates for cut precious or semi-precious stones, such as diamonds, include specific details that specify the characteristics of the stone's cut and the quality of the cut.

[0009] The certificate includes a cross-sectional view of the cut gemstone or semi-precious stone, its value, and measurements of the angle between the facets and the long axis of the cut gemstone or semi-precious stone. This cut also provides information about the quality of the cut and complements the cut grading. Cut grading is provided, especially in the case of diamonds, in addition to other factors indicating the quality of the cut gemstone or semi-precious stone (the 4Cs: cut, color, clarity, and carat).

[0010] A cut gemstone or semi-precious stone is defined not only by ratios such as the total height (H) measured between the table and the culet, but also by the crown height (C) and pavilion height (P) from the girdle. These values ​​are calculated between the table and the diameter of the stone (or length L measured at the girdle), and between the girdle and the aforementioned diameter (or length L measured at the girdle) of the cut gemstone or semi-precious stone. Furthermore, cut gemstones or semi-precious stones other than round brilliants are also defined by the minimum diameter (U) of the table and the minimum diameter (or width) (W) of the girdle of the cut gemstone or semi-precious stone.

[0011] The total height (H) or thickness of a cut gemstone or semi-precious stone is specified in millimeters, measured between the culet and the table of the cut stone. This value, along with the length and width of the cut gemstone or semi-precious stone, and its ratio of total height (H) to length or width (L or W), is used to specify the characteristics of the cut gemstone or semi-precious stone in the certificate.

[0012] The precise proportion quality of a cut gemstone or semi-precious stone is measured using a proportion scope, which analyzes the efficiency of light reflection from one facet to another, the dissipation achieved, and the reflection of light by the table. In fact, light rays pass through the cut gemstone or semi-precious stone, and the overall height of the stone affects the path and reflection of the light rays as they pass through the cut gemstone or semi-precious stone.

[0013] To achieve the best brilliance and cut quality dimensions, especially in the case of diamonds, the shape of the cut stone, the absence of known defects (particularly off-center table, off-center pavilion, excessively large culet, distorted contour around the girdle, deformed facets, misaligned crown and pavilion, wavy girdle, polishing streaks or scratches), the connections between the other facets of the cut stone, and even the way light reflects towards the observer at the appropriate angle all influence the outcome.

[0014] Japanese Patent Application No. 4709088 (Patent Document 1) describes not only an ideal cut gemstone (GIA type) with a pavilion cut angle of 40.75°, a crown cut angle of 34.5°, and a table diameter of 53% of the girdle diameter, but also cut gemstones with a large pavilion cut angle (P1), i.e., between 40° and 46°, and a crown angle (C) between 14° and 37°.

[0015] European Patent Application No. 1110472 (Patent Document 2), with reference to Figure 3, describes a cut gemstone in which the cut angles of the first crown facet (25), second crown facet (26), third crown facet (27), and fourth pavilion facet (28) are 10°~25°, 10°~25°, 25°~35°, 35°~55°, and 25°~35°, respectively. This patent application also mentions that the cut angles of the third facet (27) and fourth facet (28) can be 30°~42°, and that the cut angles of facets 27 and 28 can be 25°~35°, 35°~55°, or 30°~42°, respectively.

[0016] U.S. Patent No. 11,633,323 (Patent Document 3), with reference to Figure 4, states that the cut angle values ​​of facets 32A, 32B, and 34 are obtained by supplementally cutting a base of a cut diamond having a cut angle of 25° to 60°, preferably 32° to 38°, and 36° to 42° for the other facets.

[0017] British Patent No. 4343652 (Patent Document 4) describes a diamond with facets cut at a cut angle of 20° to 70°.

[0018] Swiss Patent No. 713602 (Patent Document 5) describes a stone cut into a small star shape for easy incorporation into a watch dial and a method for manufacturing the same, and the cut angles of facets a, b, c, and d cut from the crown of the cut stone are 15°~23°, 18°~26°, 24°~32°, and 36°~44°, respectively.

[0019] However, gemstones or semi-precious stones cut in their original shape, as is common in prior art, have dimensions, particularly thickness, that is, the overall height of the cut gemstone or semi-precious stone, that make them unsuitable for optimal integration into any timepiece, especially for placement on exterior watch components such as the dial flange or case back, or the clasp of a watch or wristlet.

[0020] In reality, the maximum thickness of the stone that can be incorporated is limited by the thickness of the dial and the space provided between the dial and the hands to avoid obstructing the movement of the hands, assuming that the cut stone extends across the entire thickness of the dial.

[0021] Therefore, in order to optimally incorporate cut precious or semi-precious stones into the flange of a timepiece or the back cover of the dial of a timepiece such as a wristwatch, it is an issue to manufacture a precious or semi-precious stone of an appropriate size, more specifically, a very thin precious or semi-precious stone with the smallest possible overall height without breakage, while maintaining the brilliance and beauty characteristics required for decorating a timepiece, particularly a high-quality wristwatch.

Prior Art Documents

Patent Documents

[0022]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0023] An object of the present invention is to manufacture cut precious or semi-precious stones such as diamonds and to provide a manufacturing method without any drawbacks of the prior art.

[0024] More specifically, the present invention aims to manufacture precious or semi-precious stones, preferably cut into a marquise cut or a brilliant cut, that maintain the brilliance characteristics and an attractive aesthetic appearance required for decorating a timepiece, particularly a high-quality wristwatch, or a high-class jewelry item, while minimizing the overall height (H) between the culet and the table (T) of the cut stone.

[0025] The present invention further aims to produce cut precious or semi-precious stones that do not become brittle and can be set in jewelry.

[0026] Finally, the present invention aims to produce cut precious or semi-precious stones that are true to the plan and preferably certified by an international certification body such as GIA, AGS, HRD, GSI, EGL, SSEF, or GRS, and retain the brilliance characteristics required to be certified as having a good, very good, excellent, or even ideal quality (according to AGS standards).

Means for Solving the Problems

[0027] The present invention relates to cut precious or semi-precious stones such as diamonds, preferably precious or semi-precious stones with fancy cuts such as marquise cut or brilliant cut.

[0028] For these purposes, the cut precious or semi-precious stones according to the present invention, their manufacturing methods, and the shatons used therefor, as well as the dials and timepieces (especially wristwatches), or jewelry are defined according to the appended claims.

[0029] The inventors have found that for the exterior parts of timepieces, especially the rims of wristwatches or the back covers of dials, cut stones with an overall height (H) measured in millimeters and a diameter or length (L) measured in millimeters having a ratio less than 0.50, preferably 0.50 - 0.40, and more specifically about 0.43, are advantageously used, where the overall height of the cut stone is advantageously low.

[0030] The cut precious or semi-precious stones according to the present invention have a crown with the table at the top, a pavilion, and a girdle at the boundary between the crown and the pavilion, and more specifically, are cut stones with either a marquise cut or a brilliant cut.

[0031] The cut gemstone or semi-precious stone according to the present invention may be a diamond or gemstone selected from the group consisting particularly of emeralds, rubies, and sapphires, but may also be a cut stone of so-called "fine" stones such as spinel, tourmaline, topaz, amethyst, citrine, peridot, tanzanite, aquamarine, or garnet.

[0032] In the cut gemstone or semi-precious stone according to the present invention, the facet surface P2 has a cut angle of 35° to 45°, and the facet surface P4 has a cut angle of 25° to 35°.

[0033] According to a preferred embodiment of the present invention, the cut gemstone or semi-precious stone according to the present invention also has a specific cut facet having one or more of the following features on the other facets: - The cut angle of the facet surface P1 is 35° to 45°, preferably about 40°. - The cut angle of facet surface P3 is 25° to 35°, preferably about 30°. - The cut angle of facet surface P5 is 37° to 47°, preferably about 42°. - The cut angle of facet surface P6 is 37.5° to 47.5°, preferably about 42.5°. - The cut angle of facet surface P7 is 38° to 48°, preferably about 42.59°.

[0034] According to the present invention, “cut angle of a cut gemstone or semi-precious stone” means the angle (degrees or °) measured between a facet or pavilion facet and the plane formed by the stone’s girdle or, optionally, the plane of the table of the cut stone. The cut gemstones or semi-precious stones according to the present invention are of the fancy type and have a size and number of facets that correspond to the generally accepted regulations for each cut type of such stones, making it possible to give them optimal brilliance and an attractive aesthetic appearance while ensuring suitability for setting in a dial or another high-quality watch or jewelry.

[0035] The present invention also relates to timepiece or jewelry components incorporating cut precious or semi-precious stones according to the present invention, particularly to timepiece clasps or dials.

[0036] Preferably, these components of the timepiece or jewelry are fitted with fastening means that are virtually invisible to the user and that can attractively showcase the cut gemstone or semi-precious stone according to the present invention.

[0037] Another aspect of the present invention relates to a method for obtaining a cut gemstone or semi-precious stone according to the present invention, wherein at least one step of polishing the treated stone surface is performed on either a raw gemstone or semi-precious stone (including a raw diamond) or a cut gemstone or semi-precious stone (including a cut diamond) according to the proportions of the present invention to obtain a cut gemstone or semi-precious stone according to the proportions of the present invention.

[0038] First, the raw or cut gemstone or semi-precious stone is subjected to known processes associated with cutting gemstones or semi-precious stones, including cleavage, sawing, rough cutting, and lateral cutting, prior to one or more polishing steps for producing the cut gemstone or semi-precious stone according to the present invention.

[0039] The object, advantages, and features of the present invention are described in detail in the descriptive section with reference to the accompanying drawings. The drawings are presented as preferred, non-limiting examples of the present invention. [Brief explanation of the drawing]

[0040] Figures 1A to 1F illustrate a cut stone according to the present invention, having a crown with a table at the top, a pavilion, and a girdle at the boundary between the crown and the pavilion, with various facets or pavilions of the crown and pavilion labeled. [Figure 1A] This is a cross-sectional view of a conventional brilliant-cut diamond, with the facets labeled with symbols. [Figure 1B] This is a side view of the cut stone according to the present invention, with the facets labeled with reference numerals. [Figure 1C] This is a side view of the cut stone according to the present invention, with the facets labeled with reference numerals. [Figure 1D] This is a side view of a conventional brilliant-cut diamond, with the facets labeled with symbols. [Figure 1E] This is a side view of the cut stone according to the present invention, with the facets labeled with reference numerals. [Figure 1F] This is a perspective view of the same cut stone according to the present invention. [Modes for carrying out the invention]

[0041] The present invention relates to cut gemstones or semi-precious stones and methods for manufacturing or cutting them, as well as jewelry in which the cut gemstones or semi-precious stones are set, for example, on the dial of a timepiece, particularly on the dial of a watch or on the flange of a dial, using a timepiece, particularly on the dial or clasp of a watch, or a fastening means used to secure the cut gemstones or semi-precious stones. The present invention also relates to the setting of such cut gemstones or semi-precious stones in chatons and incorporating them to form part of jewelry.

[0042] The present invention will be described in more detail with respect to diamonds of all colors, but may also relate to all ornamental stones called precious or semi-precious stones, especially cut gemstones, namely diamonds, emeralds, rubies, and sapphires, as well as cut so-called "fine" stones such as spinel, tourmaline, topaz, amethyst, citrine, peridot, tanzanite, aquamarine, and garnet.

[0043] The attached figures show some schematic diagrams of cut gemstones or semi-precious stones according to the present invention. As shown in the attached figures, cut gemstones or semi-precious stones according to the present invention can be manufactured to have a total of 23 facets, consisting of 12 pavilion facets, 5 girdle facets, and 5+1 crown facets.

[0044] In the cut gemstone or semi-precious stone according to the present invention, the preferred ratios between various measurements of the cut gemstone or semi-precious stone according to the present invention, as shown in the attached drawings, are as follows: L / W=1.56; T / W=1.280; U / W=0.759; V / W^3=0.172; P / W=0.318; C / W=0.047; H / W=0.383 and P / C=6.843.

[0045] Furthermore, the cut gemstone or semi-precious stone according to the present invention is also characterized by the degree value (°) of its measured angle. The angle values ​​in the table below correspond to the cut angle of the facet or pavilion of the cut gemstone or semi-precious stone. According to the present invention, a margin or difference of approximately plus or minus 5° may be provided for the cut angle value of the cut gemstone or semi-precious stone according to the present invention.

[0046] The cut gemstones or semi-precious stones according to the present invention can be set and incorporated into a timepiece and have the advantage of retaining the brilliance characteristics required for the cut to be certified as good, very good, excellent, or even ideal quality (according to AGS standards) by international certification bodies such as GIA, AGS, IGI, HRD, GSI, EGL, SSEF, or GRS.

[0047] facet G1: 90.00 P1:40.00 G2: 90.00 P2:40.00 P3:30.00 P4:30.00 P5:42.00 P6:42.50 P7:42.59 T:0.00 Table C1:25.00 25.00 [Explanation of symbols]

[0048] T Table H Total height C Crown Height P Pavilion Height L Length U table diameter W girdle width

Claims

1. A cut gemstone or semi-precious stone having a crown with a table at the top, a pavilion, and a girdle at the boundary between the crown and the pavilion, characterized in that the cut angle of facet P2 is 35° to 45°, the cut angle of facet P4 is 25° to 35°, and the ratio of the total height (H) to the diameter or length (L) of the cut gemstone or semi-precious stone is less than 0.

5.

2. The ratio of the total height (H) to the diameter or length (L) of the cut gemstone or semi-precious stone is 0.5 to 0.4, and more specifically, about 0.43, according to claim 1.

3. - The cut angle of the facet surface P1 is 35° to 45°, preferably about 40°. - The cut angle of the facet surface P3 is 25° to 35°, preferably about 30°. - The cut angle of facet surface P5 is 37° to 47°, preferably about 42°. - The cut angle of facet surface P6 is 37.5° to 47.5°, preferably about 42.5°. - The cut angle of facet surface P7 is 38° to 48°, preferably about 42.59°. The precious stone or semi-precious stone according to claim 1.

4. A cut gemstone or semi-precious stone according to claim 1, characterized in that it is marquise cut or brilliant cut.

5. A cut gemstone or semi-precious stone according to claim 1, characterized in that it is a diamond.

6. A cut gemstone or semi-precious stone according to claim 1, characterized in that it is a gemstone.

7. The cut gemstone or semi-precious stone according to claim 6, characterized in that it is a fine stone selected from the group consisting of spinel, tourmaline, topaz, amethyst, citrine, peridot, tanzanite, aquamarine, and garnet.

8. A component of a timekeeping device having an opening for housing a chaton for a cut gemstone or semi-precious stone, as described in claim 1.

9. The component of the timer according to claim 8, characterized in that the component of the timer is a frame.

10. A timer including a cut gemstone or semi-precious stone or a timer component as described in claim 1.

11. The timekeeping device according to claim 10, characterized in that it is a wristwatch.

12. A chaton comprising a base for setting a cut gemstone or semi-precious stone as described in claim 1.

13. Jewelry comprising a cut gemstone or semi-precious stone as described in claim 1 or a chaton as described in claim 12.

14. A method for producing a cut precious or semi-precious stone according to claim 1, comprising one or more steps of polishing the surface of the precious or semi-precious stone.

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