Method for cutting diamond and diamond proportion

Abstract

To provide a diamond rendering reflective light off the table goldenly brilliant by making a proportion thereof symmetry at any place viewed from an upper face, a side face or a bottom face, first reference lines, second reference lines crossing the first reference lines at right angles and third reference lines equally dividing the first reference lines and the second reference lines into four equal parts, respectively are provided. A first arc line is made by intersections of the reference lines. The approximately regular hexadecagon shaped table is established by connection of the intersections of the reference lines with the first arc line. Fourth reference lines dividing the third reference lines into two equal parts and a second arc line with a circle concentric with and larger than the first arc line is made. Star facets are established by connection of the intersections among the fourth reference lines and the second arc line with the top of the table. Upper main facets are established by connection of intersections of a diamond outward appearance and the first and the third reference lines with intersections of the fourth reference lines and the second arc line.

1 . A method for cutting a diamond having a girdle, a crown formed on an upper side of the girdle and provided with a table at an upper portion thereof, and a pavilion formed on a lower side of the girdle, comprising the steps of: 
 providing a first reference line on a diamond, providing on the diamond a second reference line crossing the first reference line at right angles thereto, providing on the diamond third reference lines dividing a sector between the first and second reference lines into four equal parts, providing on the diamond a first arc-connected line having a diameter equal to that of the table and passing an intersection of these reference lines, and connecting intersections of these reference lines and first arc-connected line together to define the table of a substantially 16-cornered right polygonal shape,    providing on the diamond fourth reference lines dividing sectors between the third reference lines into two equal parts to form a second arc-connected line concentric with and larger than the first arc-connected line, connecting intersections of the fourth reference lines and second arc-connected line and a center of the table together to define star facets,    connecting intersections of an outermost edge of the diamond and first to third reference lines and intersections of the fourth reference line and second arc-connected line together to establish upper main facets, and paired upper girdle facets between the upper main facets and the outermost edge of the diamond, and    cutting the diamond along the contours of the established facets.    
   
   
       2 . A diamond cutting method according to  claim 1 , wherein the table is cut by setting a maximum diameter of the table to substantially 53% of the diameter of the girdle with respect to a base percentage of 100% representing the diameter of the girdle.  
   
   
       3 . A diamond cutting method according to  claim 1 , wherein the diamond is cut by setting the height of the diamond as a whole, the height of the crown, the height of the pavilion and a maximum width of the girdle to substantially 66.4%, substantially 15.7%, substantially 50% and substantially 1.3% respectively with respect to a base percentage of 100% representing the diameter of the girdle.  
   
   
       4 . A diamond cutting method according to  claim 1 , wherein the diamond is cut by setting an angle to be formed between the reference line of the girdle and crown to substantially 33°.  
   
   
       5 . A diamond cutting method according to  claim 1 , wherein the diamond is cut by setting an angle to be formed between the reference line of the girdle and pavilion to substantially 42° to 48°.  
   
   
       6 . Proportions of a diamond having a girdle, a table-carrying crown formed on an upper side of the girdle, and a pavilion formed on a lower side of a girdle, 
 the diamond being formed by setting the height of the diamond as a whole, the height of the crown, the height of the pavilion and a maximum width of the girdle to substantially 66.4%, substantially 15.7%, substantially 50% and substantially 1.3% respectively with respect to a base percentage of 100% representing a diameter of the girdle,    a maximum diameter of the table being set to substantially 53% of the diameter of the girdle to form the table to a substantially 16-cornered right polygonal shape and define star facets, upper main facets and upper girdle facets,    the pavilion being divided into areas by keel lines opposed to the substantially 16-cornered right polygonal shape,    lower girdle facets and lower main facets being formed in each divisional area with a culet formed in a central section of a bottom portion of the pavilion.    
   
   
       7 . Proportions of a diamond according to  claim 6 , wherein: the diamond has 65-faced cuts established by the table provided on the crown, star facets, upper main facets and upper girdle facets, 
 49-faced cuts being established by the lower girdle facets, lower main facets and culet which are formed on the pavilion,    a total of 114-faced cuts being established.    
   
   
       8 . Proportions of a diamond according to  claim 6 , wherein the cuts in all faces except the culet have substantially symmetric proportions when the diamond is seen from any of an upper surface, a side surface and a bottom surface thereof.  
   
   
       9 . Proportions of a diamond according to  claim 6 , wherein the diamond has an angle of substantially 33° formed between the reference line of the girdle and crown.  
   
   
       10 . Proportions of a diamond according to  claim 6 , wherein the diamond has an angle of substantially 42° to 48° formed between the reference line of the girdle and pavilion.