CN107105839B

CN107105839B - Gemstone, in particular faceted diamond, and method of mounting same on a mount

Info

Publication number: CN107105839B
Application number: CN201580064978.7A
Authority: CN
Inventors: R·莫伊斯; M-A·洛
Original assignee: Cartier International AG
Current assignee: Cartier International AG
Priority date: 2014-12-02
Filing date: 2015-11-30
Publication date: 2020-08-14
Anticipated expiration: 2035-11-30
Also published as: EP3226713B1; EP3226713A1; CN107105839A; WO2016086323A1; JP6807839B2; JP2017536183A; US20180042345A1

Abstract

The invention relates to a gemstone (10) having a crown (12), a pavilion (13), and an intermediate portion, called a girdle (14), between the crown (12) and the pavilion (13). It has a metal fixing element (20) designed to allow fixing thereof to said base, said metal fixing element (20) comprising a connection zone (21) located on said pavilion (13). The joining zone (21) is located on a part or all of the peripheral sector (131) of said pavilion (13) of limited width, wherein the incident ray (R3) on the crown (12) enters the gemstone (10) through the air/gemstone interface, is reflected by the first pavilion/air interface at a point of the pavilion (13) lower than said joining zone (21), or is totally reflected by said first pavilion/air interface of said gemstone (10) in the peripheral sector (131) having said joining zone (21).

Description

Gemstone, in particular faceted diamond, and method of mounting same on a mount

Technical Field

The present invention relates to a gemstone made of natural or synthetic material, in particular a faceted diamond, said gemstone comprising a visible forehead portion, called crown (crown), and a back portion, called pavilion (pavilion), which is at least partially hidden when the gemstone is mounted on a table, and which is separated from the crown portion by an intermediate portion, called girdlet, between said crown portion and said pavilion portion, said gemstone comprising a fixing element enabling it to be fixed on said table, said fixing element comprising a metal connecting zone located on said pavilion portion.

And to a method of mounting a gemstone as defined above on a base, said gemstone comprising a fixing element arranged so as to enable it to be fixed to the base, said fixing element comprising a metal attachment zone located at said pavilion.

Background

Gemstones, particularly diamonds, are designed to be fixed to a base or a support, for example to form a jewel or a clock. According to one known embodiment, the fixing of the gemstone on the base is accomplished by depositing a metal coating on part of the peripheral surface of the gemstone, said metal coating making it possible to fix the gemstone tightly to the base by welding, riveting or the like.

By way of example, publication FR 2,042,156a describes a gemstone on the pavilion of which a metal layer is deposited. The metal layer allows the gemstone to be welded to the substrate. However, this arrangement has the disadvantage of being unsightly, since this metallization layer is visible, due to the fact that: some of the incident rays reflected by the exit interface located within the metallized region of the gemstone will be returned by the gemstone by total reflection and back to the image of the metallized layer.

The publication JP 09173115a describes a technique for fixing a gemstone, such as diamond, on a substrate, wherein a first layer, for example an alloy containing titanium (Ti), copper (Cu), silver (Ag) and/or zirconium (Zr), is deposited on the diamond, and a second metal layer, for example a gold (Au) alloy, is deposited on the substrate. The two metal layers are then welded together to securely hold the diamond to the substrate. The metal layer is deposited on the pavilion of the diamond, more specifically, on the middle of the pavilion and on the surface smaller than the total surface of the pavilion of the diamond. For the same reasons as described above, this technique has the aesthetic disadvantage that the metal layer is visible when the incident rays reflected in the metallized areas in the gemstone exit through the crown of the gemstone.

Publication WO 00/57743 a2 relates to a system capable of rolling precious stones (crimp) in a hollow item of jewellery. The system comprises means for creating a metallic fixation zone on the surface of the precious stone and attachment means for securing the metallic fixation zone to the housing of the hollow item of jewellery. To create the metal fixation zone, a circumferential portion of the surface of the precious stone is metalized, and a metal layer is deposited by electrolysis on the metalized circumferential portion of the surface of the precious stone. The securing band is formed in a hollow groove within the gemstone and at least partially intrudes onto the forehead (i.e., crown) of the gemstone.

Publication WO2014/030068 a2 relates to a support comprising precious stones, a mounting surface and a soldered joint. The braze joint is formed from a reactive metal alloy that allows certain points on the precious stone surface to adhere directly to the mounting surface. However, the fixing technique described in this publication risks not providing a sufficiently reliable or efficient maintenance of the gemstone, and the described brazing method requires high temperatures (typically over 800 ℃), which consumes considerable energy and may potentially damage the delicate mounting surface of the base for the top-grade gemstone.

The problems caused by fixing the gemstone to the base include: effective and reliable maintenance of the gemstone is ensured without the need for high processing temperatures for fixing, and this fixing is made virtually invisible so as not to destroy the brilliance of the gemstone. The known art does not provide a satisfactory solution to these problems.

Disclosure of Invention

The present invention aims to overcome the above-mentioned drawbacks by proposing a gemstone arranged to be invisibly fixed on its base and a method of fixing a gemstone on its base, the fixing obtained being effective, reliable, durable and invisible.

To this end, the invention relates to a gemstone as defined in the preceding paragraph, characterized in that said joining zone is located over part or all of a peripheral sector of said pavilion of limited width, wherein an incident ray on the crown penetrating the gemstone via the air/gemstone interface is reflected by a first pavilion/air interface at a point of said pavilion below said joining zone, or is totally reflected by said first pavilion/air interface of said gemstone in said peripheral sector including said joining zone, and is refracted outside the gemstone behind said pavilion by at least one second pavilion/air interface of said gemstone.

According to a preferred embodiment, said peripheral sector is located on said pavilion and close to said waistline. The peripheral sector may preferably comprise a so-called invisible zone in which there is no incident ray refracted at the air/crown interface reflected by the first pavilion/air interface. The peripheral sector may advantageously comprise a band extending 360 ° around the pavilion. The belt preferably covers an area corresponding to at least about 20% to 35% of the surface of the pavilion.

Particularly advantageously, the metal fixing element may comprise a plurality of metal layers deposited in a sandwich manner. The plurality of metal layers preferably comprises an inner layer which forms a carbide layer with the gemstone. According to an advantageous embodiment, the inner layer comprises titanium, tantalum, hafnium or niobium.

The plurality of metal layers also preferably comprises an outer layer comprising the same material as the base for receiving the gemstone. Preferably, the outer layer and the base comprise gold. According to another embodiment, the plurality of metal layers comprises an intermediate layer forming a diffusion barrier between the inner layer and the outer layer. The intermediate layer may comprise platinum. Advantageously, the metal fixation element is deposited using a PVD method.

Also for this purpose, the invention relates to a method of fixation as defined above, characterized in that said connection zone is deposited on a part or all of a peripheral sector of said pavilion of limited width, wherein the incident rays on the crown that penetrate the gemstone via the air/gemstone interface are reflected by the first pavilion/air interface at a point of said pavilion below said connection zone, or are totally reflected by said first pavilion/air interface of said gemstone in the peripheral sector containing said connection zone, and are refracted outside the gemstone behind said pavilion by at least one second pavilion/air interface of said gemstone.

In the case of this method, it is advantageous that the peripheral sector is defined at the pavilion and close to the waistline. Advantageously, a band is deposited in said peripheral sector covering a zone corresponding to at least about 20% to 35% of the surface of said pavilion. The belt advantageously covers at least about 20% to 35% of the area corresponding to the surface of the pavilion.

In the case of this method, a plurality of metal layers may be deposited in a sandwich manner to form the metal fixing element. An inner layer forming a carbide layer with the gemstone may also be deposited, the inner layer comprising titanium, tantalum, hafnium or niobium. It is also possible to deposit an outer layer prior to fixing the gemstone, the outer layer comprising the same material as the base used to receive the gemstone.

Drawings

The invention and its advantages will be better presented in the following description of an embodiment provided as a non-limiting example with reference to the accompanying drawings, in which:

FIG. 1 is an axial cross-sectional view of a gemstone, schematically illustrating the trajectory of light rays penetrating the crown of the gemstone and returning from the crown after being totally reflected at first and second pavilion/air interfaces,

fig. 2 is an axial cross-section of a gemstone, schematically illustrating the trajectory of light rays penetrating into the crown of the gemstone, said gemstone being provided with a joining zone on a limited sector of the pavilion,

fig. 3 is an axial cross-section of a gemstone, schematically illustrating the trajectory of a ray of light penetrating into the crown of the gemstone, said gemstone being provided with a joining region in the non-visible region,

figure 4 is a side view of a gemstone according to the invention provided with said attachment zone,

fig. 5 is a bottom view of a gemstone of the invention provided with said attachment zone.

Detailed Description

The present invention relates to a gemstone, hereinafter referred to as "gemstone" 10. The gemstone 10 of the present invention may be natural or synthetic, and may be composed of faceted diamonds in particular, but may also be composed of emerald, sapphire, ruby or other types of stones. In the illustrated example, gemstone 10 is a round drill having a plurality of cut facets 11. This exemplary embodiment is of course not limiting and the invention relates to various shapes of gemstones.

Referring to the drawings, gemstone 10 is shown to include a brow portion, commonly referred to as crown 12, which is visible when gemstone 10 is secured to a base (not shown). Which is typically cut to have a plurality of facets 11. Behind the crown 12, the gemstone 10 includes a back, commonly referred to as a pavilion 13, defined relative to the crown 12 by a middle, commonly referred to as a girdle 14. The pavilion 13 is generally cut at a point, and may also have a plurality of facets 11. Typically, pavilions 13 are at least partially concealed when the stone is mounted on its base. Indeed, pavilion 13 is typically used to allow gemstone 10 to be fixed on a base such that only crown 12 is visible, while ensuring that the fixation of gemstone 10 is as invisible as possible. One goal sought by jewelers is to hide the way in which the gemstone 10 is fixed, while ensuring that the gemstone 10 is reliably fixed and is accompanied by an optimal gloss or brilliance, whatever the application, regardless of the type of base (which may consist, for example, of a clock or jewelry).

As shown particularly in fig. 1, incident light rays R1, R2 penetrating gemstone 10 through crown 12 may undergo one or several total reflections at the gemstone/air interface in pavilion 13, depending on the size of facet 11 of gemstone 10, so that the incident light returns through the gemstone/air interface of crown 12 and imparts brilliance and a desired aesthetic to gemstone 10. For reference, at point A1 along angle i₁(with respect to the normal H at the incident point A1 of the ray R1_A1) Light ray R1 incident on facet 11 of crown 12 of gemstone 10 penetrates gemstone 10 and undergoes a refraction phenomenon at the air/gemstone interface of crown 12. According to Snell-Descarates law, the refractive index n of air is adjusted₁And refractive index n of gemstone 10₂Angle of incidence i₁And angle of refraction i₂The associated relationship is written as:

n₁sin(i₁)＝n₂sin(i₂)

refracted ray R'1 is relative to normal H_A1Deviation angle i₂The angle i₂Angle of incidence i less than angle of incidence R1₁Because of the refractive index n of air₁Lower than the refractive index n of the gemstone 10₂. This refracted ray R'1 propagates within gemstone 10 and strikes the wall of pavilion 13, and more specifically the first pavilion/air interface at point B1, where it undergoes total reflection. In practice, refracted ray R'1 is at point B1 with respect to normal H_B1Form an angle i_rGreater than the limit angle i_lBeyond this limit angle, total reflection occurs, which obeys the following law:

I_l＝arcsin(n₁/n₂)。

for example, for the refractive index n₂2.42 gem diamond10 and refractive index n of air₁Case equal to 1, limit angle i_lSubstantially equal to 24. Next, reflected ray R'1 follows angle i at point B1_rIs passed to point C1 at the second pavilion/air interface where it undergoes a new total reflection and then returns to point D1 at the third crown/air interface. It undergoes refraction at point D1 so that exit angle i₄Greater than the angle of incidence i₃. It should be noted that the incident light at point a1 of crown 12 returns to point D1 of crown 12 as ray R "1, so that when the above conditions are met, gemstone 10 glows its entirety.

The second incident light beam R2 is shown in fig. 1. The light beam R2 passes in a substantially perpendicular manner to the central extent 121 of the crown 12 while traveling in a straight line without undergoing any refraction at the point of incidence a 2. It penetrates gemstone 10 and reaches the first pavilion/air interface where it undergoes a first total reflection at point B2 and then a second total reflection at point C2 of the second pavilion/air interface. The light exits substantially perpendicular to the central extent 121 of the crown 12 without undergoing any refraction. As previously mentioned, the incident light returns after following a more or less complex optical path within stone 10.

Under the foregoing conditions, and assuming that the surface of pavilion 13 is metallized or partially or completely covered with an opaque coating in order to provide fixation elements for fixing stone 10 to a base, at least a portion of the light that has passed through stone 10 and has been reflected by the surface provided with said opaque coating will send back an image of the opaque coating and destroy the desired brilliance of stone 10, which is sought to be avoided.

To this end, the gemstone 10 of the present invention as illustrated by fig. 2-4 is provided with a metal fixing element 20 to allow it to be fixed to a base (not shown). In this embodiment, these metal fixing elements 20 comprise a connection zone 21 located on part or all of the limited peripheral sectors 131 of the pavilion 13. The metal fixing elements 20 do not modify the normal course of travel of light, but are located in the peripheral sectors 131 so that they are not visible. In fact, the peripheral sector 131 of the pavilion 13 has particular optical properties, as will be explained in the rest of the description. As shown in fig. 5, the connecting region 21 may take the form of a metal band 22 extending completely around (i.e., covering 360 °) the pavilion. The belt 22 may be located directly below the waist portion 14. Metal strip 22 may be formed by a metal coating or layer having a limited width with respect to the height of pavilion 13 and extending at least partially on peripheral sector 131 of pavilion 13. Thus, the peripheral sector 131 may be partially or fully metallized depending on the base. Preferably, peripheral sector 131 comprises a metal band 22 covering an area corresponding to 20% to 35% of the surface of pavilion 13.

By way of example, as shown in fig. 2, incident ray R3 is delivered to one facet 11 of the crown 12 of the gemstone 10 at an incidence point A3 near the waistline 14. It should be noted that the ray R3 is sent to the facet 11 adjacent to the waistline 14. Which penetrates crown 12 in the form of refracted ray R'3, while normal H at point a3, close to facet 11_A3And falls on the first pavilion/air interface of pavilion 13 in peripheral sector 131 where metal band 22 is deposited. Ray R'3 undergoes total reflection at point B3. Due to this total reflection, it is at less than the limit angle i_lReturns to point C3 on the second pavilion/air interface of the opposite side facet 11 of the pavilion 13, the incident rays below this limit angle no longer undergo total reflection but are refracted. This is true for light rays reflected at peripheral sector 131, which are refracted by the second pavilion/air interface of pavilion 13 as they exit gemstone 10. Therefore, the peripheral sector 131 of the pavilion 13 has a characteristic of not returning light under a condition that allows the second total reflection on the second pavilion/air interface. Thus, the image of the metallized or opaque metal bands 22 located in this peripheral sector 131 is not visible in front of the gemstone 10, i.e. the observer will not see the joining region 21 of the gemstone 10, since the metal bands 22 acting as fixing elements 20 will not be visible when viewing the crown 12.

A second ray of light R4, shown in fig. 2, is refracted at entry point a4 on crown 12, and while penetrating gemstone 10 in the form of ray R '4, R'4 is reflected at point B4 on the first pavilion/air interface, below metal band 22. After its total reflection, it is incident at a point C4 of the second pavilion/air interface on the opposite side of the first pavilion/air interface, and undergoes a second total reflection at this point C4. It is then reflected toward the crown 12, traversing the crown 12 at point D4 while undergoing refraction. Ray R4 rejoins rays R1 and R2 of fig. 1 with respect to its optical trajectory and returns the incident light while helping to impart brilliance to gemstone 10. The light ray R4 is not reflected in the peripheral sector 131 and can be seen by an observer.

As shown in fig. 3, the peripheral sector 131 also contains a so-called invisible zone ZI, in which the incident ray R3 refracted at the air/crown interface can be reflected only by the first pavilion/air interface outside said invisible zone ZI. In other words, no light is reflected in the invisible region. The invisible zone ZI is located below the waist portion and has a height depending on the height of the waist portion, which is typically 2% to 6% of the diameter of the jewel. For example, when gemstone 10 has a diameter of 2mm, the width of the invisible region in this case may be 0.25 mm. If a metal band 22 is provided that is narrow enough to be within the invisible zone ZI, any incident ray at the air/crown interface will be reflected at the first pavilion/air interface outside the band 22. Thus, metal strip 22 will not be visible because no light can reach the invisible region. In this case, the connection region 21 including the band 22 does not completely cover the peripheral sector 131.

Thus, the particular optical properties of the peripheral sectors 131 make it possible to deposit the joining zone 21 on part or all of the peripheral sectors 131, thereby making it invisible to an observer viewing the gemstone 10 through the crown 12. It has been observed in a faceted round drill that the peripheral sector 131 is located directly below the waistline 14 and extends over a surface that is smaller than the total area of the pavilion 13.

According to one embodiment of the invention, the metal fixing element 20 is deposited on the surface of the gemstone using a PVD (physical vapor deposition) process. The use of PVD makes it possible to form the connecting zone 21 on the surface of the gemstone in a controlled and precise manner. The step of cleaning the surface of the gemstone, and optionally the step of depositing an adhesion layer, may be performed prior to the PVD deposition step. Preferably, the PVD deposition step is carried out in a chamber containing an inert gas (e.g., argon) at 10^-4mbar～10^-2mbarUnder pressure.

In one embodiment, the metal fixation element 20 comprises a plurality of metal layers deposited in a sandwich fashion on the surface of the gemstone. According to a particular alternative, an inner metal layer of titanium (or a titanium-based alloy), then an intermediate layer made of platinum (or a platinum-based alloy), then an outer layer of gold (or a gold-based alloy) are deposited on the gemstone first. Here, the thickness of the titanium layer is preferably 40nm to 500nm, which functions as adhesion, and the titanium and the gem stone form a carbide layer. Other materials capable of forming a carbide layer with the gemstone (e.g., tantalum, hafnium, or niobium) may alternatively be used in place of titanium as the inner layer. The thickness of the gold outer layer is preferably 100nm to 2000nm, which allows for fixation to the gold base by soldering or by hot pressing, as described below. Of course, if the base for receiving the gemstone is made of another material, the material of the outer layer may be adjusted accordingly. The thickness of the platinum layer is preferably 60nm to 500nm, which forms a diffusion barrier between the titanium layer and the gold layer, but other materials may be used as an intermediate layer. Other layers than those already mentioned may also be present in the fixing element 20.

As explained in detail above, after the metal fixing element 20 is formed on the surface of the gemstone, a chemical cleaning step may be performed to eliminate any metallic material present in unwanted locations to ensure that the attachment zone 21 is properly located and is not discernible.

After metallization, the stones containing the metal fixing elements 20 may be fixed to the respective bases using different techniques, but preferably by hot pressing or welding. In the case of hot pressing, and preferably also in the case of welding, a metal layer is also formed by means of a PVD method on part of the surface of the base intended to receive the gemstone (in particular in the metal fixing element 20). In particular, for a gold susceptor, the metal layer deposited on the susceptor is also preferably made of gold. The step of cleaning the surface of the susceptor as discussed may also be performed before the deposition of the metal layer on the susceptor.

According to an alternative, the stone is fixed to the base by hot pressing, and a metal fixing element 20 comprising an outer layer of gold is pressed onto the layer of gold deposited on the base. In one example of the above-described method,in this step a compressor was used, which was at 2kg/mm²～20kg/mm²Is operated at a temperature of from 100 c to 600 c (or more preferably from 200 c to 450 c) for a time of from 20 seconds to 60 minutes.

According to another alternative, the welding machine is used to weld at 5g/mm²～50g/mm²The force of (a) is operated at a temperature of 280 to 350 c for a duration of 1 second to 5 minutes to fix the gemstone to the base. As mentioned above, in this case a preform of suitable material and having a suitable shape is used (for example a conical ring made of gold-tin), and the susceptor preferably has a layer of gold previously deposited on its surface. A chemical cleaning step may be performed after soldering to eliminate any remaining debris.

Feasibility of industrial application

The present description clearly shows that: the metal band 22 is indistinguishable because it is present in the invisible region ZI just below the waist portion; alternatively, at the first pavilion/air interface where metal band 22 is located, all incident rays R3 reflected by peripheral sector 131 are at an angle less than the limit angle of total reflection i_lIs returned to the second pavilion/air interface so that it refracts and scatters behind and is not visible at the pavilion 13 of the gemstone 10. The present invention achieves the desired objective that the joint region 21 of the gemstone 10 is not visible when the joint region 21 is secured to its base.

The use of a PVD method to deposit the metal fixation elements 20 on the pavilions makes it possible to form the metal connection zones 21 with controlled dimensions and precise positions. Preferably, this connection zone 21 extends 360 ° around the pavilion like the metal band 22, which allows a reliable and stable fixation to the base even when the stone is small and the width of the band 22 is relatively thin. Furthermore, the gemstone comprising the metal fixing element 20 may advantageously be fixed to a base at a temperature not exceeding 600 ℃, more preferably not exceeding 450 ℃.

The invention is not limited to the exemplary embodiments described, but extends to any modifications and alternatives apparent to those skilled in the art.

Claims

1. Gemstone (10) made of natural or synthetic material, said gemstone (10) comprising a visible frontal portion, called crown (12), and a back portion, at least partially hidden when said gemstone (10) is mounted on a base, said back portion being called pavilion (13) and being separated from said crown (12) by an intermediate portion, called waistline (14), between said crown (12) and said pavilion (13), said gemstone (10) comprising a metallic fixation element (20) arranged to enable said gemstone (10) to be fixed on said base, said metallic fixation element (20) comprising a connection zone (21) located on said pavilion (13), said gemstone (10) being characterized in that said connection zone (21) is located on part or all of a peripheral sector (131) of said pavilion (13) of limited width,

wherein the peripheral sector (131) is arranged to:

when the incident ray (R3) on the crown (12) penetrating into the gemstone (10) via the air-gemstone interface falls within the peripheral sector (131) containing the joining zone (21), it is totally reflected in the peripheral sector (131) by the first pavilion-air interface of the gemstone (10) and then at less than a limit angle i_lIs returned to a second pavilion-air interface of the opposite side facet (11) of said pavilion (13), the incident rays below said limit angle no longer undergo total reflection and are refracted out of said gemstone (10) behind said pavilion (13) through said second pavilion-air interface; and is

When a line of incidence (R4) on said crown (12) penetrating said gemstone (10) via an air-gemstone interface falls below said peripheral sector (131) of said first pavilion-air interface, it is totally reflected by said first pavilion-air interface, then enters a second pavilion-air interface opposite said first pavilion-air interface, undergoes a second total reflection there, and is reflected toward said crown (12);

wherein said peripheral sector (131) comprises a band (22) extending 360 ° around said pavilion (13), said band (22) covering at least a zone corresponding to 20% -35% of the surface of said pavilion (13).

2. The gemstone according to claim 1, wherein the peripheral sector (131) is located on the pavilion (13) and near the girdle (14).

3. The gemstone according to claim 1, wherein said peripheral sector (131) includes a so-called invisible Zone (ZI) in which there is no incident ray (R3) refracted at the air-crown interface reflected by said first pavilion-air interface.

4. Gemstone according to claim 1, characterized in that the metallic fixation element (20) comprises a plurality of metallic layers deposited in a sandwich manner.

5. The gemstone according to claim 4, wherein the plurality of metal layers includes an inner layer that forms a carbide layer with the gemstone.

6. The gemstone according to claim 5, wherein the inner layer comprises titanium, tantalum, hafnium or niobium.

7. The gemstone according to claim 4, wherein the plurality of metal layers includes an outer layer comprising the same material as the base for receiving the gemstone.

8. The gemstone according to claim 7, wherein the outer layer and the base comprise gold.

9. The gemstone according to claim 4, wherein the plurality of metal layers includes an intermediate layer forming a diffusion barrier between the inner and outer layers.

10. The gemstone according to claim 9, wherein the intermediate layer comprises platinum.

11. The gemstone according to claim 9, wherein the gemstone is a faceted diamond.

12. The gemstone according to any of the preceding claims, wherein the metallic fixation element is deposited using a PVD method.

13. A method of mounting a gemstone (10) on a base, the gemstone (10) being made of natural or synthetic material, the gemstone (10) comprising a visible forehead, referred to as a crown (12), and a back, at least partially hidden when mounted on the base, the back being referred to as a pavilion (13) and being separated from the crown by an intermediate portion, referred to as a girdle (14), between the crown and the pavilion, the gemstone (10) comprising a metallic fixation element (20) arranged to enable the gemstone (10) to be fixed on the base, the metallic fixation element (20) comprising a connection zone (21) located on the pavilion (13), the method being characterized in that the connection zone (21) is deposited on a portion or on the whole of a peripheral sector (131) of the pavilion (13) of limited width, depositing a band (22) in said peripheral sector (131) and extending 360 ° around said pavilion (13), said band (22) covering an area corresponding to at least 20% -35% of the surface of said pavilion (13);

wherein the peripheral sector (131) is arranged to:

When a line of incidence (R4) on said crown (12) penetrating said gemstone (10) via an air-gemstone interface falls below said peripheral sector (131) of said first pavilion-air interface, it is totally reflected by said first pavilion-air interface, then it is incident on a second pavilion-air interface opposite said first pavilion-air interface, and undergoes a second total reflection there, and is reflected toward said crown (12).

14. A method as claimed in claim 13, wherein said peripheral sector is defined in said pavilion (13) and adjacent to said waistline (14).

15. A method as claimed in claim 13, characterized in that a plurality of metal layers are deposited in a sandwich manner to form the metal fastening element (20).

16. The method of claim 15, wherein an inner layer is deposited that forms a carbide layer with the gemstone, the inner layer comprising titanium, tantalum, hafnium, or niobium.

17. The method of claim 15, wherein an outer layer comprising the same material as the base for receiving the gemstone is deposited.

18. The method of claim 15, wherein an intermediate layer forming a diffusion barrier between the inner layer and the outer layer is deposited.

19. Method according to claim 13, characterized in that the metallic fixation element (20) is deposited by means of a PVD method.

20. The method of claim 19, wherein the PVD method comprises at 10^-4mbar～10^-2PVD deposition is carried out in a closed space containing an inert gas at a pressure of mbar.

21. The method of claim 13, wherein the gemstone is affixed to the base by heat and pressure.

22. The method of claim 21, wherein the step of,characterized in that the base is provided with a base with the weight of 2kg/mm²～20kg/mm²The metal fixing member (20) is pressed at a temperature of 100 to 600 ℃ for 20 seconds to 60 minutes.

23. The method of claim 22, wherein the pressing temperature is from 200 ℃ to 450 ℃.

24. The method of claim 13, wherein said gemstone is secured to said base by welding.

25. The method of claim 24, wherein the base is positioned at 5g/mm²～50g/mm²The metal fixing element (20) is welded at a temperature of 280-350 ℃ for 1 second-5 minutes.

26. A method according to claim 25, wherein a preform is used.

27. The method of claim 13, wherein the gemstone is a faceted diamond.

28. A method according to any one of claims 13 to 27, wherein a layer of metal is deposited on the part of the surface of the base which is intended to receive the gemstone, prior to fixing the gemstone.