Gemstone and methods of cutting the same

Abstract

A gemstone includes a crown, a pavilion, and a girdle disposed between the crown and the pavilion. The girdle has an elliptical-shaped cross-section with first and second pointed ends. The surface of the gemstone is generally divided into a number of groups of interlocking facets disposed at a variety of angles. The groups of facets comprising the surface of the crown generally include star facets, upper intermediate crown facets, lower intermediate crown facets, main crown facets, and upper girdle facets. The upper girdle facets generally abut an upper edge of the girdle. The groups of facets comprising the surface of the pavilion include culet-adjacent facets, candle facets, main pavilion facets, and lower girdle facets. The lower girdle facets generally abut a lower edge of the girdle.

What is claimed is: 
     
         1 . A gemstone comprising:
 a girdle defining a perimeter of the gemstone, the girdle having an elongated elliptical-shaped cross-section, the elliptical-shaped cross-section having a first pointed end and a second pointed end opposing the first pointed end;   a crown forming an upper portion of the gemstone, a surface of the crown including:
 a table forming a generally horizontal upper surface of the crown; 
 a plurality of star facets, each of the plurality of star facets being disposed adjacent to and abutting an edge of the table; 
 a plurality of upper intermediate crown facets, each of the plurality of upper intermediate crown facets being disposed generally between two of the plurality of star facets, an upper vertex of each of the plurality of upper intermediate crown facets abutting a vertex of the table; 
 a plurality of lower intermediate crown facets, each of the plurality of lower intermediate crown facets being disposed generally between two of the plurality of upper intermediate crown facets, an upper vertex of each of the plurality of lower intermediate crown facets abutting a lower vertex of one of the plurality of star facets; 
 a plurality of main crown facets, each of the plurality of main crown facets being disposed generally between two of the plurality of lower intermediate crown facets, an upper vertex of each of the plurality of main crown facets abutting a lower vertex of one of the plurality of lower intermediate crown facets; and 
 a plurality of upper girdle facets formed in pairs of adjacent upper girdle facets, each pair of adjacent upper girdle facets being disposed generally between two of the plurality of main crown facets, upper vertices of both upper girdle facets in each pair of upper girdle facets abutting a lower vertex of one of the plurality of lower intermediate crown facets; and 
   a pavilion forming a lower portion of the gemstone, a surface of the pavilion including:
 a plurality of culet-adjacent facets forming a lower point of the pavilion; 
 a plurality of candle facets, a lower portion of each of the plurality of candle facets being disposed generally between two of the plurality of culet-adjacent facets; 
 a plurality of main pavilion facets, each of the main pavilion facets being disposed between two of the plurality of candle facets, a lower edge of each of the plurality of main pavilion facets abutting an upper edge of one of the plurality of culet-adjacent facets; and 
 a plurality of lower girdle facets formed in pairs of adjacent lower girdle facets, each pair of adjacent lower girdle facets being disposed generally between two of the plurality of main pavilion facets, each pair of adjacent lower girdle facets having an upper portion of a respective one of the plurality of candle facets disposed generally therebetween; and 
   wherein the girdle is positioned between the crown and the pavilion, each of the plurality of upper girdle facets being disposed adjacent to and abutting an upper edge of the girdle, and each of the plurality of lower girdle facets being disposed adjacent to and abutting a lower edge of the girdle.   
     
     
         2 . The gemstone of  claim 1 , wherein the gemstone has a table percentage between about 20 percent and about 34 percent. 
     
     
         3 . The gemstone of  claim 1 , wherein the gemstone has a top depth percentage between about 15 percent and about 35 percent. 
     
     
         4 . The gemstone of  claim 1 , wherein the gemstone has a bottom depth percentage between about 35 percent and about 40 percent. 
     
     
         5 . The gemstone of  claim 1 , wherein the gemstone has a total depth percentage between about 85 percent and about 95 percent. 
     
     
         6 . The gemstone of  claim 1 , wherein the gemstone has a girdle thickness percentage between about 5 percent and about 15 percent. 
     
     
         7 . The gemstone of  claim 1 , wherein a horizontal plane is defined by the table of the gemstone, and wherein each of the plurality of star facets is disposed at a first angle relative to the horizontal plane, each of the plurality of upper intermediate crown facets is disposed at a second angle relative to the horizontal plane, each of the plurality of lower intermediate crown facets is disposed at a third angle relative to the horizontal plane, each of the plurality of main crown facets is disposed at a fourth angle relative to the horizontal plane, and each of the plurality of upper girdle facets is disposed at a fifth angle relative to the horizontal plane. 
     
     
         8 . The gemstone of  claim 7 , wherein first angle is between about 6° and about 18°. 
     
     
         9 . The gemstone of  claim 7 , wherein the second angle is between about 8° and about 15°, between about 17° and about 25°, or both. 
     
     
         10 . The gemstone of  claim 7 , wherein the third angle is between about 20° and about 30°, between about 28° and about 36°, or both. 
     
     
         11 . The gemstone of  claim 7 , wherein the fourth angle is between about 28° and about 36°, between about 43° and about 50°, between about 39° and about 48°, or combinations thereof. 
     
     
         12 . The gemstone of  claim 7 , wherein the fifth angle is between about 48° and about 60°. 
     
     
         13 . The gemstone of  claim 1 , wherein a horizontal plane is defined by the table of the gemstone, and wherein each of plurality of culet-adjacent facets is disposed at a first angle relative to the horizontal plane, each of plurality of candle facets is disposed at a second angle relative to the horizontal plane, each of plurality of main pavilion facets is disposed at a third angle relative to the horizontal plane, and each of the plurality of lower girdle facets is disposed at a fourth angle relative to the horizontal plane. 
     
     
         14 . The gemstone of  claim 13 , wherein the first angle is between about 23° and about 29°. 
     
     
         15 . The gemstone of  claim 13 , wherein second angle is between about 25° and about 35°, between about 38° and about 44°, or both. 
     
     
         16 . The gemstone of  claim 13 , wherein the third angle is between about 25° and about 35°, between about 35° and about 45°, between about 42° and about 48°, or combinations thereof. 
     
     
         17 . The gemstone of  claim 13 , wherein the fourth angle is between about 36° and about 50°. 
     
     
         18 . The gemstone of  claim 1 , wherein the first and second pointed ends have a same profile. 
     
     
         19 . The gemstone of  claim 1 , wherein the elliptical-shaped cross-section is symmetric across a first axis an extending between the first and second pointed ends. 
     
     
         20 . The gemstone of  claim 19 , wherein the elliptical-shaped cross-section is symmetric across a second axis that is perpendicular to the first axis.