Abstract:
A gemstone includes a crown portion and a girdle portion abutting the crown portion and extending along a predetermined plane. The crown portion has a plurality of crown facets provided on a surface thereof. The crown portion and the girdle portion each have eight longitudinal sections. At least one of the eight longitudinal sections of the crown portion have a first facet of the crown facets having a first edge bordering the girdle portion, and a second facet of the crown facets having a second edge bordering the girdle portion. A particular portion of the first edge abuts the second edge at a particular location. The first and second edges curve toward a center of the gemstone which is provided on the particular plane. The particular location is closer to the center of the gemstone than another portion of the first edge.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a gemstone which has a particular shape, and which has a particular number of facets on the crown, girdle, and pavilion portion thereof. In particular, the gemstone may have a shape of a sunflower or other similar shape. 
     BACKGROUND INFORMATION 
     Generally, facets on precious and semi-precious gemstones are cut so as to provide a brilliance to these gemstones in an economical manner. The way to cut the gemstones to provide particular facets thereon and the locations of these facets on the gemstones are well known in the art. FIGS. 1-4 show an exemplary illustration of a conventional gemstone  10  having a circular shape as viewed from top view (FIG.  4 ). However, it is possible that another embodiment of the gemstone  10  may have other shapes (e.g. an oval shape, a marquis shape, etc.). The conventional gemstone  10  has a prior art configuration of facets on the surface of the gemstone  10 . In particular, FIG. 1 shows a side view of the conventional round-shaped gemstone  10 . The conventional gemstone  10  includes a crown  20  and a pavilion  30 . The crown  20  is provided above the pavilion  30 , and is separated from the pavilion  30  by a girdle  40 . The crown  20  and the pavilion  30  have particular facets provided thereon. As known to those having ordinary skill in the art, these facets are arranged to enhance the brilliance of the gemstone  10 . FIG. 2 shows separate portions of the conventional gemstone  10 , i.e., the crown  20 , the pavilion and an enlarged illustration of the crown  40 . 
     FIG. 3 shows an enlarged side view and FIG. 4 shows an enlarged top view of the crown  20  of the conventional gemstone  10 . The crown  20  includes a flat table  50  which has a shape of an octagon and is disposed primarily in the horizontal plane on top of the crown  20 . In addition, facets are provided on a diagonally extending side  25  of the crown  20 . These facets include star facets  110  (each having a shape of a triangle), upper main facets  120  (each having four sides), left-side upper girdle facets  130  (each having a pointed end directed to the left side), and right-side upper girdle facets  140  (each having a pointed end directed to the right side). The crown generally has eight star facets  110 , eight upper main facets  120 , eight left-side upper girdle facets  130  and eight right-side upper girdle facets  140 . Accordingly, the crown  20  has a total of thirty-two (32) facets and the table  50  (which can be considered as another facet) provided thereon. 
     The longest edges  115  of the star facets  110  form edges  55  of the table  50 . A right edge  118  of each star facet  110  forms a shorter left edge  126  of a respective upper main facet  120 . A left edge  117  of each star facet  110  forms a shorter right edge  128  of another upper main facet  120 . A right edge  137  of each left-side upper girdle facet  130  forms a longer left edge  124  of a respective upper main facet  120 , while a left edge  135  of the same left-side upper girdle facet  130  forms a longer right edge  122  of another upper main facet  120 . Bottom edges  138  of the left-side upper girdle facets  130  and bottom edges  148  of the right-side upper girdle facets  140  collectively form an upper edge  45  of the girdle  40 . 
     FIG. 5 shows an enlarged side view and FIG. 6 shows an enlarged bottom view of the pavilion  30  of the conventional gemstone  10 . The pavilion  30  includes facets on a diagonally extending side  35  of the pavilion  30 . These facets include left-side lower girdle facets  150  (each having a shape of a triangle), right-side lower girdle facets  160  (each having a shape of a triangle), and lower main facets  170  (each having four sides). The pavilion generally has eight left-side lower girdle facets  150 , eight right-side lower girdle facets  160 , and eight lower main facets  170 . Accordingly, the pavilion  30  has a total of twenty-four (24) facets provided thereon. 
     Each of the left edge  157  of the left-side lower girdle facets  150  form the longer right edge  175  of the lower main facet. Each of the right edge  155  of the left-side lower girdle facets  150  form the left edge  165  of the right-side lower girdle facets  160 . Each of the right edge  167  of the right-side lower girdle facet  160  form the longer left edge  176  of the lower main facet. Each of the shorter left edge  177  of the lower main facet  170  form the shorter right edge  178  of the lower main facet  170 . Top edges  158  of the left-side lower girdle facets  150  and top edges  168  of the right-side lower girdle facets  160  form a lower edge of the girdle  40 . 
     Using this configuration of the facets of the crown  20 , is was possible to obtain a brilliance effect and appeal with the conventional gemstone  10  which was generally acceptable to a consumer. 
     SUMMARY OF THE PRESENT INVENTION 
     An object of the present invention is to provide a brilliance effect and appeal with a gemstone for a consumer. 
     In order to achieve these objectives as well as others that will become apparent with reference to the following specification, the present invention provides a gemstone and a method for making the gemstone. In one arrangement, the gemstone includes a crown portion and a girdle portion abutting the crown portion and extending along a predetermined plane. The crown portion has a plurality of crown facets provided on a surface thereof. The crown portion and the girdle portion each have eight longitudinal sections. At least one of the eight longitudinal sections of the crown portion have a first facet of the crown facets having a first edge bordering the girdle portion, and a second facet of the crown facets having a second edge bordering the girdle portion. A particular portion of the first edge abuts the second edge at a particular location. The first and second edges curve toward a center of the gemstone which is provided on the particular plane. The particular location is closer to the center of the gemstone than another portion of the first edge. Preferably, a particular portion of the second edge abuts the first edge at the particular location, and the particular location is closer to the center of the gemstone than another portion of the second edge. Advantageously, a pavilion portion including a number of pavilion facets provided on the surface thereof, and the girdle portion abuts with the pavilion portion and extends along the predetermined plane. 
     In an especially preferred arrangement, the pavilion portion of the gemstone has eight longitudinal sections, wherein at least one of the eight longitudinal sections of the pavilion portion has a third facet of the pavilion facets having a third edge bordering the girdle portion and a fourth facet of the pavilion facets having a fourth edge bordering the girdle portion. A particular portion of the third edge abuts the fourth edge at a further location. The third and fourth edges curve toward the center of the gemstone provided on the particular plane. The further location is closer to the center of the gemstone than another portion of the third edge. Preferably, a particular portion of the fourth edge abuts the third edge at the further location, and the further location is closer to the center of the gemstone than another portion of the fourth edge. 
     In accordance with another preferred arrangement, a method of making the gemstone is provided. According to the method, the gemstone is provided with a crown portion and a girdle portion, the crown portion extending along a predetermined plane, a first facet of the crown portion has a first edge abutting the girdle portion of the gemstone. A second facet of the crown portion of the gemstone has a second edge abutting the girdle portion of the gemstone, wherein a particular portion of the first edge abuts the second edge at a particular location. The method executes successive cuts in the gemstone such that the first edge and the second edge curve towards a center of the gemstone wherein the center is provided on the particular plane, and wherein the particular location is closer to the center of the gemstone than another portion of the first edge. 
     In accordance with another preferred arrangement, the gemstone includes a crown portion including a plurality of crown facets provided on a surface thereof, and a girdle portion abutting the crown portion and extending along a predetermined plane. The crown portion and the girdle portion of the gemstone each have at least five lobes. Advantageously, a pavilion portion including a plurality of pavilion facets provided on the surface thereof. The girdle portion abuts with the pavilion portion and extends along the predetermined plane. The pavilion portion has at least five lobes. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further objects, features, and advantages of the present invention will become apparent upon consideration of the following detailed description of the presently preferred embodiments when taken in conjunction with the accompanying drawings, wherein: 
     FIG. 1 shows a side view of a conventional gemstone; 
     FIG. 2 shows a side view of different portions of the conventional gemstone; 
     FIG. 3 shows an enlarged side view of a crown of the conventional gemstone of FIG.  1  and facets provided on the crown; 
     FIG. 4 shows an enlarged top view of the crown of the conventional gemstone of FIG.  1  and facets provided on the crown; 
     FIG. 5 shows an enlarged side view of a pavilion of the conventional gemstone of FIG.  1  and facets provided on the crown; 
     FIG. 6 shows an enlarged bottom view of the pavilion of the conventional gemstone of FIG. 1; 
     FIG. 7 shows an enlarged side view of an exemplary embodiment of the gemstone according to the present invention; 
     FIG. 8 shows a side view of the different portions of the gemstone of FIG. 7; 
     FIG. 9 shows an enlarged top view of the gemstone illustrated in FIG. 7; 
     FIG. 10 shows an enlarged bottom view of the gemstone illustrated in FIG. 7; 
     FIG. 11 shows yet further enlarged views of corresponding sections of the crown of the gemstone prior to any cutting thereof; and 
     FIG. 12 shows the corresponding sections of the crown and pavilion of FIG. 11 after a portion thereof is cut; and 
     FIG. 13 shows the corresponding sections of the crown and pavilion of FIG. 11 after a further portion thereof is cut; and 
     FIG. 14 shows the corresponding sections of the crown and pavilion of FIG. 11 after a still further portion thereof is cut; and 
     FIG. 15 shows a side view of the gemstone illustrated in FIG. 7 with relative dimensions of particular portions of the gemstone being provided. 
    
    
     DETAILED DESCRIPTION 
     An exemplary embodiment of a gemstone  200  according to the present invention is shown in FIGS. 7-14. FIG. 7 shows an enlarged side view of the gemstone  200  which has an eight-lobed shape as viewed from the top or the bottom (e.g., see FIGS.  8  and  9 ). However, it is possible that another embodiment of the gemstone  200  of the present invention may have other shapes (e.g., a five-lobed shape, a six-lobed shape, a seven-lobed shape, a nine-lobed shape, etc.). It is also possible that still another embodiment of the gemstone  200  of the present invention may have an eight lobed shape when viewed from the top but not when viewed from the bottom, and vice versa. The gemstone  200  can be a precious stone (such as a diamond) or a semi-precious stone. 
     Similarly to the conventional gemstone  10  of FIG. 1, the gemstone  200  according to the present invention as illustrated in FIGS. 7 and 8 includes a crown  220 , a pavilion  230 , a girdle  240 , and particular facets provided on the crown  220  and the pavilion  230 . The crown  220  is provided above the pavilion  230 , and is separated from the pavilion  230  by the girdle  240 . The crown  220  and the pavilion  230  have particular facets provided thereon. As known to those having ordinary skill in the art, these facets are arranged to enhance the appearance of the gemstone  200 . Unlike the conventional gemstone  10  of FIG. 1, the gemstone  200  according to the present invention has particular facets provided upon the girdle. FIG. 8 shows separate enlarged portions of the gemstone  200 , i.e. the crown  220 , the pavilion  230  and of the girdle  240 . 
     FIG. 9 shows an enlarged top view of the crown  220  of the gemstone  200 . The crown  220  preferably includes a flat table  350  which has a shape of an octagon and is disposed on top to the crown  220  substantially in the horizontal plane. In addition, facets are provided on a diagonally-extending side  225  of the crown  220  (as shown in FIG.  8 ). These facets include star facets  310  (each having a shape of a triangle), upper main facets  320  (each having four sides), left-side upper round girdle facets  420 , and right-side upper round girdle facets  410 . The crown generally has eight star facets  310 , eight upper main facets  320 , eight left-side upper round girdle facets  420  and eight right-side upper round girdle facets  410 . Accordingly, the crown  220  has a total of thirty-two facets and the table  350  (which can be considered as another facet) provided thereon. 
     The longest edges  315  of the star facets  310  form edges of the table  350 . A right edge  318  of each star facet  310  forms a shorter left edge  324  of a respective upper main facet  320 . A left edge  317  of each star facet  310  forms a shorter right edge  322  of another upper main facet  320 . A right edge  425  of each left-side upper round girdle facet  420  forms a longer left edge  328  of a respective upper main facet  320 , while a left edge  428  of the same left-side upper round girdle facet  420  forms an upper edge  245  of the girdle  240 . A left edge  415  of each right-side upper round girdle facet  410  forms a longer right edge  326  of a respective upper main facet  320 , while a right edge  418  of the same right-side upper round girdle facet  41   0  forms an upper edge  245  (FIG. 8) of the girdle  240 . 
     FIG. 10 shows an enlarged bottom view of the pavilion  230  of the gemstone  200 . The pavilion  230  includes facets on a diagonally-extending side  235  of the pavilion  230 . These facets include left-side lower round girdle facets  430 , right-side lower round girdle facets  440 , and lower main facets  370  (each having four sides). The pavilion generally has eight left-side lower round girdle facets  430 , eight right-side lower round girdle facets  440 , and eight lower main facets  370 . Accordingly, the pavilion  230 , preferably has a total of twenty-four (24) facets provided thereon. 
     Each of the left edge  435  of the left-side lower round girdle facets  430  forms the longer right edge  376  of the respective lower main facet  370 . Each of the right edge  437  of the left-side lower round girdle facets  430  abuts the left edge  447  of the right-side lower round girdle facets  440 . Each of the right edge  445  of the right-side lower round girdle facet  440  form the longer left edge  378  of the respective lower main facet  370 . Each of the shorter left edge  372  of the lower main facet  370  abuts the shorter right edge  374  of another lower main facet  370 . Top edges  438  of the left-side lower round girdle facets  430  and top edges  448  of the right-side lower girdle facets  440  form a lower edge  248  of the girdle  240  (as shown in FIG.  8 ). 
     It should be noted that the facets  410 ,  420 ,  430 , and  440  can be provided or produced by cutting particular sections of the crown  20 , the pavilion  30 , and the girdle  40  of the conventional gemstone  10 . Each of the sections of the crown  20  to be cut are provided between one respective left-side upper girdle facet  130  and one respective right-side upper girdle facet  140  on the crown  20  of the conventional gemstone  10  and between one respective left-side lower girdle facet  150  and one respective right-side lower girdle facet  160  of the pavilion  30  of the conventional gemstone  10 . These sections are preferably cut so that the portions of the respective left-side and right-side upper girdle facets  130 ,  140  have substantially equal but opposite surface areas, and the portions of the respective left-side and right-side lower girdle facets  150 ,  160  also have substantially equal but opposite surface areas. According to the present invention, the gemstone  10  is cut substantially along the vertical plane through the crown  20 , the girdle  40 , and the pavilion  30 . Thus, the surface areas of the facets  410  and  420  should be substantially the same, and the surface areas of the facets  430  and  440  should also be substantially the same. 
     The facets  410 ,  420 ,  430 , and  440  are provided by making a number of cuts through the gemstone  200 , and the facets are provided in pairs. FIGS. 11-14 show the steps of the process for cutting the facets  410 ,  420 ,  430 ,  440  according to the present invention. FIG. 11 shows the first step (i.e., a first cut) for creating the rounded facets on the crown  220 . A first dashed box  500  shows a portion of the crown  220 , and a second dashed box  550  shows a portion of the pavilion  230 . A cutting knife  560  is used to make the cut in the gemstone  200 . The cutting knife  560  has two portions i.e., a left portion  562  and a right portion  564 . The right portion  562  and the left portion  564  are first positioned at an obtuse angle θ 1 . The center of the cutting knife  560  is positioned at the edge between a left-side upper girdle facet  340  and a right-side upper girdle facet  330 . The right portion  562  of the cutting knife  560  extends over the right-side upper girdle facet  330  to the edge between the right-side upper girdle facet  330 , the upper main facet  320 , and the girdle  240 . The left portion  562  of the cutting knife  560  extends over the left-side upper girdle facet  330  to the edge between the left-side upper girdle facet  330 , the upper main facet  320 , and the girdle  240 . The cut is made into the crown  220 , the girdle  240 , and the pavilion  230  of the gemstone  200  substantially along the vertical plane of the gemstone  200 . 
     FIG. 12 shows the second step (i.e. a second cut) to create the rounded facets  410 ,  420 ,  430 , and  440  of the gemstone according to the present invention. The first dashed box  500  shows an enlarged portion of the crown  220 , and the second dashed box  550  shows a portion of the pavilion  230 . The angle θ 1  between the left portion  564  and the right portion  562  of the cutting knife  560  is reduced to θ 2 . The center of the cutting knife  560  is then positioned between the facets  340 ,  330 , and closer to the center of the gemstone  200 . The right portion  562  and the left portion  564  of the cutting knife  560  extend over the respective right-side upper girdle facet  330  and the respective left-side upper girdle facet  340 . The outer portions of the cutting knife  560  are preferably positioned closer together for the second cut. After the cutting knife  560  is repositioned, the second cut can be made. 
     FIG. 13 shows another step of the method of the present invention, in which the cutting knife  560  makes another cut in the gemstone  200  to form the curved edges of facets  330 ,  340 ,  350  and  360 . The angle θ 2  between the left portion  564  and the right portion  562  of the cutting knife  560  is further reduced to θ 3 . The center of the cutting knife  560  is positioned between the facets  340 ,  330 , and closer to the center of the gemstone  200 . The right portion  562  and the left portion  564  of the cutting knife  560  extend over the respective right-side upper girdle facet  330  and the respective left-side upper girdle facet  340 . The outer portions of the cutting knife  560  are preferably positioned closer together for the second cut at θ 3 . After the cutting knife  560  is repositioned, this cut can be made. 
     FIG. 14 shows the completed right-side upper round girdle  410 , left-side upper round girdle  420 , right-side lower round girdle  440 , and left-side lower round girdle  430  of the gemstone  200 . Using the method of the present invention, the edges of the right-side upper girdle facet  330  and the left-side upper girdle facet  340  which border on the girdle  240  are formed in a curved manner. Indeed, they curve toward a center of the gemstone  200 . This process can be repeated at the juncture of any two facets. 
     To further explain the gemstone  200  of the present invention, the gemstone  200  can be conceptually subdivided into eight longitudinally-extending sections  610 - 680 , as shown in FIG.  15 . In particular when viewed from above, each section of the gemstone  200  includes at least one left-side upper round girdle facet  420 , at least one right-side upper round girdle facet  410 , at least one star facet  310 , and at least one partial upper main facet  320 . Thus, as viewed from the top, at least two facets  420 ,  410  of each section have edges that border the girdle  240 . And when viewed from below, each section of the gemstone  200  includes at least one left-side lower round girdle facet  430 , at least one right-side lower round girdle facet  440 , and at least one partial lower main facet  370 . Thus, as viewed from the bottom, at least two facets  430 ,  440  of each section have edges that border the girdle  240 . According to the present invention, it is also conceivable that each of the sections  610 - 680  has other facets that border the girdle. 
     FIG. 15 also illustrates side views of the gemstone  200  according to the present invention with relative exemplary dimensions of particular portions of the gemstone being provided therein. In particular, the relative diameter λ of the girdle  240  of the gemstone  200  is set at 100%, and extends in a direction A along the diameter λ. As such, the diameter λ of the girdle  240  shall serve for the description below as a reference for other dimensions of the gemstone  200  according to the present invention. A diagonal side  225  of the crown  220  may extend at a crown angle β of between approximately 32° and 37° as measured with respect to the upper edge  245  of the girdle  240 . A diagonal side  235  of the pavilion  230  may extend at a pavilion angle α of between approximately 40° and 45° as measured with respect to the extension of the plane of the bottom edge  248  of the girdle  240 . 
     A width Φ t  of the table  350  is approximately 53% to 66% in comparison with the diameter λ of the girdle  240 . The crown  220  has a crown height h c  (measured from the table  350  of the crown  230  to an upper edge  243  of the girdle  240 ) of approximately 11% to 16% compared to the diameter λ of the girdle  240 . The girdle  240  has a girdle thickness a of approximately 2% to 5% in a relative comparison with the diameter λ of the girdle  240 . The pavilion  230  has a pavilion height h p  (measured from a pointed portion  238  of the pavilion  230  to a lower edge  245  of the girdle  240 ) of approximately 40% to 45% compared to the diameter λ of the girdle  240 . A total height h d  of the gemstone  200  (measured from the table  350  to the pointed portion  238  of the pavilion  230 ) may be approximately 56% to 65% compared to the diameter λ of the girdle  240 . 
     As an example, if the gemstone  200  has a carat weight of 2.5 carats, the diameter λ of the girdle  240  may be 10 mm. Accordingly, the table width Φ t  can be between 5.3 mm and 6.6 mm, the crown height h c  may be between 1.1 mm and 1.6 mm, the girdle thickness a may be between 0.2 mm and 0.5 mm, the pavilion height h p  can be between 4.0 mm and 4.5 mm, and the total height t d  is preferably between 5.6 mm and 6.5 mm. 
     The above-described relative dimensions are exemplary. Indeed, other crown, pavilion and middle facet angles, as well as different relative dimensions of the gemstone  200  are also conceivable, and are within the scope of the present invention. It should be appreciated that those skilled in the art will be able to devise numerous embodiments which, although not explicitly shown or described herein, embody the principles of the invention and are thus within the spirit and scope of the present invention.