Jewellery stone, in particular facetted diamond and method for mounting same on a mount

Abstract

A jewelry stone, having a crown, a pavilion and an intermediate part between said crown and said pavilion, referred to as the girdle is disclosed. It has metal fastening means that are designed to allow it to be fastened to said mount, comprising a connecting zone located on said pavilion. The connecting zone is located on a part of or all of a limited-width peripheral sector of said pavilion, in which incident rays on the crown pass into the stone through an air/stone interface, are either reflected by a first pavilion/air interface at a point of the pavilion that is lower than said connecting zone, or are reflected entirely by said first pavilion/air interface of said stone in the peripheral sector having said connecting zone.

1 . A jewelry stone, made from a natural or synthetic material, in particular a faceted diamond, including a visible frontal part called a crown and a dorsal part that is at least partially hidden when said jewelry stone is mounted on a mount, said dorsal part being called pavilion and being separated from said crown by an intermediate part between said crown and said pavilion, called girdle, said jewelry stone including metal fastening means arranged to allow said jewelry stone to be fastened on said mount, said metal fastening means including a connecting zone located on said pavilion, wherein said connecting zone is located on part or all of a peripheral sector with a limited width of said pavilion, in which the incident rays (R 3 ) on said crown penetrating said jewelry stone via an air/stone interface, are either reflected by a first pavilion/air interface on a point of said pavilion lower than said connecting zone or completely reflected by said first pavilion/air interface of said stone in said peripheral sector including said connecting zone, and are refracted to the outside of said jewelry stone, behind said pavilion, through at least one second pavilion/air interface of said jewelry stone. 
     
     
         2 . The jewelry stone according to  claim 1 , wherein said peripheral sector is situated on said pavilion near said girdle. 
     
     
         3 . The jewelry stone according to  claim 1 , wherein said peripheral sector includes a so-called invisible zone (ZI) in which no incident ray (R 3 ) refracted at an air/crown interface is reflected by said first pavilion/air interface. 
     
     
         4 . The jewelry stone according to  claim 1 , wherein said peripheral sector includes a band extending over 360° around the pavilion. 
     
     
         5 . The jewelry stone according to  claim 4 , wherein said band covers a zone corresponding at least approximately to about 20 to 35% of the surface of said pavilion. 
     
     
         6 . The jewelry stone according to  claim 1 , wherein said metal fastening means comprise a plurality of metal layers deposited in a sandwich. 
     
     
         7 . The jewelry stone according to  claim 6 , wherein said plurality of metal layers comprises an inner layer forming a layer of carbide with said jewelry stone. 
     
     
         8 . The jewelry stone according to  claim 7 , wherein said inner layer comprises titanium, tantalum, hafnium or niobium. 
     
     
         9 . The jewelry stone according to  claim 6 , wherein said plurality of metal layers comprises an outer layer comprising the same material as that of the mount intended to receive said jewelry stone. 
     
     
         10 . The jewelry stone according to  claim 9 , wherein said outer layer and said mount comprise gold. 
     
     
         11 . The jewelry stone according to  claim 6 , wherein said plurality of metal layers comprises an intermediate layer forming a diffusion barrier between said inner layer and said outer layer. 
     
     
         12 . The jewelry stone according to  claim 11 , wherein said intermediate layer comprises platinum. 
     
     
         13 . The jewelry stone according to  claim 1 , wherein said metal fastening means are deposited using a physical vapor deposition (PVD) method. 
     
     
         14 . A method for mounting a jewelry stone on a mount, said jewelry stone being made from a natural or synthetic material, in particular a faceted diamond, including a visible frontal part called a crown and a dorsal part that is at least partially hidden when said jewelry stone is mounted on a mount, said dorsal part being called pavilion and being separated from said crown by an intermediate part between said crown and said pavilion, called girdle, said jewelry stone including metal fastening means arranged to allow said jewelry stone to be fastened on said mount, said metal fastening means including a connecting zone located on said pavilion, wherein said connecting zone is deposited over part or all of a peripheral sector of limited width of said pavilion, in which the incident rays (R 3 ) on said crown penetrating said jewelry stone via an air/stone interface, are either reflected by a first pavilion/air interface on a point of said pavilion lower than said connecting zone or are completely reflected by said first pavilion/air interface of said stone in said peripheral sector including said connecting zone, and are refracted outside said jewelry stone, behind said pavilion, through at least one second pavilion/air interface of said jewelry stone. 
     
     
         15 . The method according to  claim 14 , wherein said peripheral sector is defined at said pavilion near said girdle. 
     
     
         16 . The method according to  claim 14 , wherein a band is deposited in said peripheral sector extending over 360° around said pavilion. 
     
     
         17 . The method according to  claim 14 , wherein said band covers a zone corresponding to at least approximately 20 to 35% of the surface of said pavilion. 
     
     
         18 . The method according to  claim 14 , wherein a plurality of metal layers are deposited in a sandwich to form said metal fastening means. 
     
     
         19 . The method according to  claim 18 , wherein an inner layer is deposited forming a layer of carbide with said jewelry stone, said inner layer comprising titanium, tantalum, hafnium or niobium. 
     
     
         20 . The method according to  claim 18 , wherein an outer layer is deposited comprising the same material as that of said mount intended to receive said jewelry stone. 
     
     
         21 . The method according to  claim 18 , wherein an intermediate layer is deposited forming a diffusion barrier between an inner layer and an outer layer. 
     
     
         22 . The method according to  claim 14 , wherein said metal fastening means are deposited using a PVD method. 
     
     
         23 . The method according to  claim 22 , wherein said PVD method includes a PVD deposition done in an enclosure comprising an inert gas at a pressure between 10 4  and 10 −2  mbar. 
     
     
         24 . The method according to  claim 14 , wherein said jewelry stone is fastened to the mount by thermal compression. 
     
     
         25 . The method according to  claim 24 , wherein said metal fastening means are compressed against said mount with a force of 2-20 kg/mm 2  and at a temperature of 100-600° C. for a duration from 20 seconds to 60 minutes. 
     
     
         26 . The method according to  claim 25 , wherein the compression temperature is 200-450° C. 
     
     
         27 . The method according to  claim 14 , wherein said jewelry stone is fastened to said mount by welding. 
     
     
         28 . The method according to  claim 27 , wherein said metal fastening means are welded against said mount with a force of 5-50 g/mm 2  and a temperature of 280-350° C. for a duration from 1 second to 5 minutes. 
     
     
         29 . The method according to  claim 28 , wherein a preform is used. 
     
     
         30 . The method according  claim 14 , wherein a metal layer is deposited on the part of the surface of said mount intended to receive said jewelry stone before fastening of said jewelry stone.