Cut stone and method for obtaining it

Abstract

The invention relates to a cut stone and its method of obtaining it, in particular a cut precious or semi-precious stone comprising a crown surmounted by a table, a pavilion and a girdle at the intersection of the crown and the pavilion, the surface of facet P2 having a cutting angle between 35° and 45°, the surface of facet P4 having a cutting angle between 25° and 35° and said cut stone has a ratio between the total height (H) and the diameter or length (L) of said cut stone, which is less than 0.50 preferably between 0.50 and 0.40 and, more particularly, of the order of 0.43.

Description

Technical field of the invention

[0001] The present invention is in the field of cutting precious and semi-precious stones, including diamonds, intended more particularly for use in the watchmaking or jewelry industry. Technological background and state of the art

[0002] In high-end watchmaking, it is known to add hard materials, such as jasper, mother-of-pearl, onyx, or precious or semi-precious stones, especially diamonds, to the dial or other components of a timepiece such as a watch or a watch clasp, or in a piece of jewelry.

[0003] To achieve a particular aesthetic effect, original shapes, including for marquetry, can be imagined. However, the arrangement of these hard materials, especially cut precious or semi-precious stones, must be done according to perfect geometry.

[0004] Indeed, optimal insertion of these hard materials, as finishing components, in particular precious or semi-precious stones cut, is a determining element of the level of quality and finish of a watch or jewelry piece, which defines the brand image of the manufacturer.

[0005] A cut precious or semi-precious stone, when viewed in cross-section, has an upper part called the crown and a lower part called the pavilion.

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

[0007] The walls of the breech, like the walls of the crown, have multiple facets, named according to their shape: star, Halefi, Bezal or corner of a table on the crown and pavilion or Halefi on the breech.

[0008] The cutting of precious or semi-precious stones, particularly diamonds, is both an art and a science. A cut precious or semi-precious stone, including a diamond, has certain specifications in its certificate to characterize the size and quality of the cut.

[0009] A certificate will present a cross-sectional view of the said cut precious or semi-precious stone with its values, as well as the measurements of the angles between the faces and the axis of the length of the cut precious or semi-precious stone. This cross-section also provides information on the quality of the cut and complements the cut rating, which is added to the other factors (the 4 Cs for Cut, Color, Clarity, and Carat) demonstrating the quality of the cut precious or semi-precious stone, particularly in the case of a diamond.

[0010] A cut precious or semi-precious stone is defined by its proportions, such as its total height (H) measured from the table to the neck, as well as by the crown height (C) and pavilion height (P) of the pavilion, when these values ​​are calculated respectively between the table and the diameter (or length (L) measured at the girdle) of the stone, and between the neck and said diameter (or length (L) measured at the girdle) of the cut precious or semi-precious stone. Furthermore, a cut precious or semi-precious stone other than a round brilliant is also defined by the smallest diameter (U) of the table and the smallest diameter (or width) (W) at the girdle of the cut precious or semi-precious stone.

[0011] The total height (H) or thickness of a cut precious or semi-precious stone is defined in mm and is measured between the culet and the table of the cut stone. This value, along with the length and width of said cut precious or semi-precious stone, as well as the ratio between its total height (H) and its length or width (L or W), defines the characteristics of a cut precious or semi-precious stone in a certificate.

[0012] The quality of the proportions of a cut gemstone or semi-precious stone is measured using a proportionscope, which assesses the efficiency of light reflected from one facet to another, the resulting dispersion, and the reflection of light by the table. Indeed, light rays enter a cut gemstone or semi-precious stone, and the overall height of the stone affects the path and reflection of these rays within the gemstone or semi-precious stone.

[0013] To achieve maximum brilliance and the highest cut quality rating, especially in a diamond, the result will depend on the shape of the cut stone, particularly the absence of known defects, such as an off-center table, an off-center pavilion, an oversized culet, a distorted girdle outline, misshapen facets, misalignment of the crown and pavilion, a wavy girdle, polishing striations or scratches, but also on the relationship with the other facets of said cut stone and therefore how the light will be reflected at the correct angle towards the observer.

[0014] Japanese patent application JP 4709088 describes 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 that represents 53% of the girdle diameter, as well as a cut stone with a pavilion cut angle (P1) of increasing value, i.e. between 40° and 46° and a crown angle (C) between 14° and 37°.

[0015] European patent application EP 1110472 describes, with reference to Figure 3, a gemstone cut with first crown facets (25), second crown facets (26), third crown facets (27), and fourth pavilion facets (28) having cutting angles between 10° and 25°, 10° and 25°, 25° and 35°, 35° and 55°, and 25° and 35°, respectively. This patent application also states that the third facets (27) and fourth facets (28) can have a cutting angle between 30° and 42°, and that facets 27 and 28 have cutting angles between 25° and 35° and between 35° and 55°, respectively, or between 30° and 42°.

[0016] US patent US 11,633,323 describes, with reference to figure 4, facet cutting angle values ​​for facets 32 A, 32 B and 34 resulting from an additional cutting of the base of a cut diamond having a cutting angle between 25° and 60°, preferably between 32° and 38° and between 36° and 42° for the other facets.

[0017] British patent GB 4343652 describes a diamond cut with facets having a cutting angle between 20° and 70°.

[0018] Swiss patent CH 713 602 describes a small star-shaped cut stone and its manufacturing process to facilitate its insertion into a watch dial and whose cut facets a, b, c and d of the crown of the cut stone have cutting angles between 15° and 23°, between 18° and 26°, between 24° and 32° and between 36° and 44° respectively.

[0019] However, the cut and original shaped precious or semi-precious stones known from earlier art have dimensions, in particular a thickness, that is to say the total height of the cut precious or semi-precious stone, which are not very compatible for optimal insertion into all watch parts, especially for arrangement on elements of a watch such as the rim or background of a dial or on a clasp of a watch or bracelet.

[0020] Indeed, the maximum thickness of the inserted stone will be limited by the thickness of the dial, assuming that the cut stone extends over the entire thickness of the dial, and by the available space between the dial and the hands, so as not to hinder the movement of the latter.

[0021] Therefore, to achieve optimal integration of a cut precious or semi-precious stone into the rim of a timepiece or into the background of a dial of a timepiece, such as a watch, the challenge is to obtain a precious or semi-precious stone of adequate size, in particular of very low thickness, i.e. with the lowest possible total height, without fracturing it and while retaining the brilliance and aesthetic properties required for the ornamentation of a timepiece, especially a quality watch. Objectives of the invention

[0022] The present invention aims to obtain a cut precious or semi-precious stone, including a diamond, and its method of obtaining it which does not present the disadvantages of the prior art.

[0023] A particular object of the present invention is to obtain such a cut precious or semi-precious stone, preferably marquise cut or brilliant cut, and which has the lowest total height (H) between the neck and the table (T) of the cut stone, while retaining the properties of brilliance and an attractive aesthetic appearance, required for the ornamentation of a timepiece, in particular on a quality watch or a piece of jewelry.

[0024] A further objective of the invention is to obtain such a cut precious or semi-precious stone which is not weakened and which can be set in a piece of jewelry.

[0025] A final objective of the invention is to obtain such a cut precious or semi-precious stone that is faithful to the plan, and preferably that has retained the required brilliance properties so that its cut can be certified as being of good quality (good, very good, excellent, or even ideal (according to the AGS body)) by an international certification body such as the GIA, AGS, Ile HRD, GSI, EGL, SSEF, or GRS. Summary of the invention

[0026] The present invention relates to a cut precious or semi-precious stone, including a diamond preferably having a fancy cut, for example marquise or brilliant cut.

[0027] For these purposes, the cut precious or semi-precious stone of the invention, its manufacturing process, the setting intended to hold it, as well as a dial and a timepiece and in particular a watch or jewelry piece are defined according to the attached claims.

[0028] The inventors have discovered that it is possible to advantageously use for the decoration of watch parts, such as edges or backgrounds of watch parts, in particular watches, cut precious or semi-precious stones which advantageously have a reduced total height and which are therefore advantageously characterized by a ratio between the total height (H) measured in mm and the diameter or length (L) measured in mm, of said cut stone, which is less than 0.50 preferably between 0.50 and 0.40 and, more particularly, of the order of 0.43.

[0029] The cut precious or semi-precious stone of the invention comprises a crown surmounted by a table, a pavilion and a girdle at the intersection of the crown and the pavilion, more particularly is such a cut stone which has a marquise cut or a brilliant cut.

[0030] The cut precious or semi-precious stone of the invention may be a diamond or a gem, in particular a gem chosen from the group consisting of emerald, ruby ​​and sapphire; but also so-called fine cut stones, such as spinel, tourmaline, topaz, amethyst, citrine, peridot, tanzanite, aquamarine or garnets.

[0031] In the cut precious or semi-precious stone of the invention, the surface of facet P2 has a cutting angle between 35° and 45° and the surface of facet P4 has a cutting angle between 25° and 35°.

[0032] According to a preferred embodiment of the invention, the cut precious or semi-precious stone of the invention also has specific facet surfaces, one or more of which have the characteristics described below: The surface of facet P1 has a size angle between 35° and 45°, preferably around 40°; the surface of facet P3 has a size angle between 25° and 35°, preferably around 30°; the surface of facet P5 has a size angle between 37° and 47°, preferably around 42°; the surface of facet P6 has a size angle between 37.5° and 47.5°, preferably around 42.5°; the surface of facet P7 has a size angle between 38° and 48°, preferably around 42.59°.

[0033] According to the invention, the cutting angle of a cut precious or semi-precious stone is defined as the angle in degrees (°) measured between the surface of a facet or the pavilion and the plane formed by the girdle of the stone or, optionally, the plane of the table of the cut stone. The cut precious or semi-precious stone of the invention is of the fancy type and will have a cut and number of facets corresponding to the recognized definition for each type of cut of these stones, thus giving it optimal brilliance and an attractive aesthetic appearance, while remaining compatible with setting on a dial or other high-quality timepiece or jewelry item.

[0034] The present invention further relates to elements of a timepiece or jewelry piece incorporating the cut precious or semi-precious stone of the invention, in particular a clasp or dial of a timepiece.

[0035] These elements of the watch or jewelry piece are preferably equipped with means of attachment, almost invisible to the user's eyes and allowing the said cut precious or semi-precious stone of the invention to be highlighted.

[0036] Another aspect of the invention relates to the process of obtaining the cut precious or semi-precious stone of the invention, in which either a rough precious or semi-precious stone (including a rough diamond) or a cut precious or semi-precious stone (including a cut diamond) is subjected to at least one or more stages of polishing the faces of the treated stone, in order to obtain the cut precious or semi-precious stone, according to the proportions of the invention.

[0037] Initially, a rough or cut precious or semi-precious stone is also subjected to the known steps of a precious or semi-precious stone cut including cleaving, sawing, roughing, cross cutting, before the polishing step(s) to obtain the cut precious or semi-precious stone of the invention.

[0038] The aims, advantages and features of the invention will be described in detail in the descriptive part with reference to the accompanying figures presented as preferred and non-limiting illustrations of the invention. Brief description of the figures

[0039] THE Figures 1A to 1F represent views of the cut stone of the invention comprising a crown surmounted by a table, with a culet and a girdle at the intersection of the crown and the culet (or pavilion), and in which the numbering of the different facets or pavilions of the crown and the culet has been introduced. Figures 1A and 1Drepresent respectively a cross-sectional view and a side view of the numbered facets of a classic "brilliant" cut diamond. figures 1B, 1C and 1E represent side views of the numbered facets of the cut stone of the invention. The figure 1F represents a perspective view of the same cut stone of the invention. Detailed description of the invention

[0040] The present invention relates to a cut precious or semi-precious stone and its method of obtaining or cutting, as well as any timepiece, in particular a watch dial or clasp, or any piece of jewelry fitted with said cut precious or semi-precious stone by fastening means implemented to fix said cut precious or semi-precious stone, for example, to the dial of a timepiece, in particular to the dial or the rim of a watch dial. This type of cut precious or semi-precious stone of the invention can also be set, incorporated into a setting, and form part of a piece of jewelry.

[0041] The invention is described more particularly for a diamond of any color, but it can also relate to any ornamental stone, whether precious or semi-precious, in particular gem-type cut stones, namely, besides diamonds, emeralds, rubies, and sapphires; but also fine cut stones, such as spinel, tourmaline, topaz, amethyst, citrine, peridot, tanzanite, aquamarine, garnets, ...

[0042] The accompanying figures show several schematic representations of a precious or semi-precious stone cut according to the invention. As shown in the accompanying figures, a precious or semi-precious stone cut according to the invention can be obtained, having 12 pavilion facets, 5 girdle facets, and 5 + 1 crown facets, for a total of 23 facets.

[0043] In the cut precious or semi-precious stone of the invention, the preferred ratio between the different measurements of the cut precious or semi-precious stone of the invention as represented in the attached figures 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.

[0044] Furthermore, the cut precious or semi-precious stone of the invention is also characterized by the degree (°) values ​​of its measured angles. In the table below, the angle values ​​correspond to the cutting angles of the faces (facets or pavilions) of the cut precious or semi-precious stone. According to the invention, a margin or difference of approximately plus or minus 5° can be provided for the cutting angle values ​​in the cut precious or semi-precious stones of the invention.

[0045] The cut precious or semi-precious stone of the invention can be set and inserted into a timepiece and advantageously retains the required brilliance properties for its cut to be certified as good, very good, excellent, or even ideal (according to the AGS organization) by an international certification body, such as the GIA, AGS, IGI, HRD, GSI, EGL, SSEF or GRS. Facets

[0046] 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

Claims

1. A cut precious or semi-precious stone comprising a crown surmounted by a table, a culet, and a girdle at the intersection of the crown and the culet. characterized in that The surface of facet P2 has a size angle between 35° and 45°. in that the surface of facet P4 has a cutting angle between 25° and 35° and a ratio between the total height (H) and the diameter or length (L) of said cut precious or semi-precious stone, which is less than 0.

5.

2. Precious or semi-precious stone according to claim 1 and comprising a ratio between the total height (H) and the diameter or length (L) of said cut precious or semi-precious stone, of between 0.5 and 0.4 and, more particularly, of the order of 0.

43.

3. Precious or semi-precious stone according to any one of the preceding claims, in which: - the surface of facet P1 has a cutting angle between 35° and 45°, preferably of the order of 40°; - the surface of facet P3 has a cutting angle between 25° and 35°, preferably of the order of 30°; - the surface of facet P5 has a cutting angle between 37° and 47°, preferably of the order of 42°; - the surface of facet P6 has a cutting angle between 37.5° and 47.5°, preferably of the order of 42.5°; and - the surface of facet P7 has a cutting angle between 38° and 48°, preferably of the order of 42.59°.

4. The precious or semi-precious stone cut according to any one of the preceding claims, characterized in that It has a marquise cut or a brilliant cut.

5. The precious or semi-precious stone cut according to any one of the preceding claims, characterized in that She is a diamond.

6. The precious or semi-precious stone cut according to any one of the preceding claims 1 to 4, characterized in that She is a gem.

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

8. Component of a timepiece comprising an opening receiving a chaton setting the precious or semi-precious stone cut according to any one of the preceding claims.

9. The timepiece component according to claim 8, characterized in that It is a clockwork part frame.

10. Timepiece comprising the cut precious or semi-precious stone or timepiece element according to any one of the preceding claims 1 to 9.

11. The timepiece according to claim 10, characterized in that It is a watch.

12. A setting comprising a housing for the precious or semi-precious stone cut according to any one of the preceding claims 1 to 7.

13. A piece of jewellery comprising the precious or semi-precious stone cut according to any one of the preceding claims 1 to 7 or the setting according to claim 12.

14. A method for obtaining the precious or semi-precious stone cut according to any one of the preceding claims 1 to 7, comprising one or more steps of polishing the faces of a precious or semi-precious stone.

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