Product with Improved Optical Characteristics

Abstract

Cut product manufactured from a rough (semi) precious stone material, more particularly from diamond, comprising a lower part (pavilion) with a bottom end (culet); an upper part (crown) with a number of facets and a top end (a point with table width 0 or a top surface (table) with a table width); and a girdle between lower part and upper part, wherein the lower part comprises a number of girdle pavilion facets which describe a first angle a 1 relative to the plane of the girdle and a number of culet facets which each describe a smaller second angle a 2 relative to the plane of the girdle; wherein the average second angle a 2 lies between 28 and 38 degrees; and wherein the ratio of the table width and the width of the girdle is 0 to 0.40.

1 .- 27 . (canceled) 
     
     
         28 . Cut product manufactured from a (semi)precious stone material, more particularly from natural or synthetic diamond, comprising:
 a lower part (pavilion) with a bottom end (culet);   an upper part (crown) with a number of facets and a top end (a point with table width  0  or a top surface (table) with a table width); and   a girdle between lower part and upper part,   wherein the lower part comprises a number of girdle pavilion facets which describe a first angle α 1  relative to the plane of the girdle and a number of culet facets which each describe a smaller second angle α 2  relative to the plane of the girdle; wherein the average second angle α 2  lies between 28 and 38 degrees; and   wherein the ratio of the table width and the width of the girdle is 0 to 0.40.   
     
     
         29 . Cut product as claimed in  claim 28 , wherein the average second angle α 2  lies between 28 degrees and 35 degrees, more preferably between 29 degrees and 33 degrees, and is for instance about 31 degrees. 
     
     
         30 . Cut product as claimed in  claim 28 , wherein each second angle α 2  lies between 25 degrees and 38 degrees, preferably between 28 degrees and 35 degrees, more preferably between 29 degrees and 33 degrees, and is for instance about 31 degrees. 
     
     
         31 . Cut product as claimed in  claim 28 , wherein the ratio of the table width and the width of the girdle is 0 to 0.30. 
     
     
         32 . Cut product as claimed in  claim 28 , wherein the top end is a table, wherein the ratio of the table width and the width of the girdle is 0.10 to 0.30. 
     
     
         33 . Cut product as claimed in  claim 28 , wherein the top end is a point. 
     
     
         34 . Cut product as claimed in  claim 28 , wherein the table width and the orientation of the facets of the upper and lower parts are optimized in order to reflect the lower part in at least a number of the facets of the upper part. 
     
     
         35 . Cut product as claimed in  claim 28 , wherein the girdle pavilion facets are located above the culet facets, wherein each culet facet adjoins the bottom end and each girdle pavilion facet adjoins the girdle. 
     
     
         36 . Cut product as claimed in  claim 28 , wherein at least three, and preferably at least four, and for instance six, seven or eight culet facets are arranged. 
     
     
         37 . Cut product as claimed in  claim 28 , wherein at least three, and preferably at least four, and for instance six, seven or eight girdle pavilion facets are arranged. 
     
     
         38 . Cut product as claimed in  claim 28 , wherein the average first angle α 1  of the girdle pavilion facets lies between 15 and 80 degrees. 
     
     
         39 . Cut product as claimed in  claim 28 , wherein the height of the cut product is the distance between the top end and the bottom end, wherein the ratio of the height of the cut product and the width of the girdle lies between 0.60 and 1, and more preferably between 0.75 and 0.85, and/or, wherein the ratio of the height of the girdle and the width of the girdle is 0.02 to 0.1. 
     
     
         40 . Cut product as claimed in  claim 28 , wherein the lower part and/or the upper part, and in particular the culet, is cut as a brilliant. 
     
     
         41 . Cut product as claimed in  claim 28 , wherein the upper part is a crown with table bezel facets and girdle bezel facets, which girdle bezel facets describe a first angle β 1  relative to the plane of the girdle, and which table bezel facets describe a second, smaller angle β 2  relative to the plane of the girdle, wherein preferably the average first angle β 1  of the girdle bezel facets relative to the plane of the girdle lies between 35 degrees and 50 degrees, preferably between 39 degrees and 43 degrees, and is more preferably about 41 degrees, and more preferably each first angle β 1  lies between 35 degrees and 50 degrees, preferably between 39 degrees and 43 degrees, and is for instance about 41 degrees. 
     
     
         42 . Cut product as claimed in  claim 41 , wherein at least three girdle bezel facets and at least three table bezel facets are arranged, preferably at least four and for instance six, seven or eight. 
     
     
         43 . Cut product as claimed in  claims 41 , wherein the girdle bezel facets are located below and adjoining the table bezel facets, wherein each table bezel facet adjoins the top end and each girdle bezel facet adjoins the girdle. 
     
     
         44 . Cut product as claimed in  claims 41 , wherein the average second angle β 2  lies between 5 and 50 degrees, preferably between 30 and 50 degrees, and for instance between 31 and 41 degrees. 
     
     
         45 . Cut product manufactured from a (semi)precious stone material, more particularly from natural or synthetic diamond, comprising:
 a pavilion with a bottom end (culet);   a crown with a number of facets and a top end (a point with table width  0  or a top surface (table) with a table width); and   a girdle between lower part and upper part,   wherein the lower part comprises a number of girdle pavilion facets which describe a first angle α 1  relative to the plane of the girdle and a number of culet facets which each describe a smaller second angle α 2  relative to the plane of the girdle;   wherein a number of bezels are provided between the top end and the girdle;   wherein the number of bezels is equal to the total of the number of girdle pavilions facets, wherein the bezels are twisted relative to the pavilions through a twist angle γ.   
     
     
         46 . Cut product as claimed in  claim 45 , wherein the twist angle is optimized as a function of the dimensions of the stone in order to obtain a reflection of the lower part in the bezels and/or in the table. 
     
     
         47 . Cut product as claimed in  claim 45 , wherein the angles α 2  and/or α 1  and/or the number of girdle and table bezel facets and the orientation thereof is/are optimized on the one hand for a cut product with the greatest possible volume and on the other for an optimum reflection of the lower part in the upper part.