Abstract:
A gemstone includes a pavilion portion, a crown portion and a girdle portion provided between the pavilion portion and the crown portion. The crown portion includes a plurality of facets provided on a surface thereof. The crown portion can have eight longitudinal sections which collectively define it. At least one of the longitudinal sections includes a predetermined number of particular facets of the plurality of facets. Each of the particular facets has at least one edge that borders the girdle portion. A single facet of the particular facets is formed from cutting at least portions of at least two further facets of the particular facets. The gemstone can also be subdivided into two longitudinal half sections, with the crown portion of which having 12 facets that border the girdle portion of the longitudinal half section.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a gemstone which has a particular number of facets on the facet portion thereof. In particular, the gemstone may include certain facets that may enhance the brilliance of the gemstone. 
     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 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 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 . 
     Using this configuration of the facets of the crown  20 , is was possible to obtain a brilliance effect with the conventional gemstone  10  which was generally acceptable to a consumer. 
     SUMMARY OF THE PRESENT INVENTION 
     The object of the present invention is to provide a better effect on a scintillation, i.e., a sparkle of the gemstone when its is irradiated in light and moved, which is caused by a light reflection of the light within the gemstone. 
     Thus, a gemstone according to an exemplary embodiment of the present invention is provided to achieve this object. The gemstone includes a pavilion portion, a crown portion and a girdle portion provided between the pavilion portion and the crown portion. The crown portion includes a plurality of facets provided on a surface thereof. The crown portion can have eight longitudinal sections which collectively define it. At least one of the longitudinal sections includes a predetermined number of particular facets. Each of the particular facets has at least one edge that borders the girdle portion. A single facet of the particular facets is formed from cutting at least portions of at least two further facets of the particular facets 
     In another embodiment of the present invention, each one of the predetermined facets includes at least one further edge that borders another one of the predetermined facets within a particular longitudinal section of the crown portion. Each of the longitudinal sections may include the predetermined number of the particular facets. All of the longitudinal sections may also have substantially the same dimensions. 
     In a further embodiment of the present invention, first four consecutive longitudinal sections can define a first half of the crown portion, and second four consecutive longitudinal sections can define a second half of the crown portion. In this embodiment according to the present invention, the first half and the second half form the crown. Additionally, all edges of the particular facets which border the girdle portion may collectively define an upper edge of the girdle portion. In addition, at least one edge of each of the particular facets which border the girdle portion may have a curved shape. 
     Another embodiment of the present invention provides that there are three facets arranged on the longitudinal section. Each of the first and second facets within a first section of the longitudinal sections have two first parallel edges. The third facet has edges which border particular parallel edges of the first and second facets. In addition, the girdle portion generally extends along a first plane, and at least one of the particular facets extends along a second plane. It is preferable for the first plane to be provided at a predetermined angle with respect to the second plane, such angle being between approximately 43.7° and 50.7°. 
     In yet another embodiment of the present invention, the gemstone can be logically subdivided into two longitudinal half sections. The crown portion of at least one the longitudinal half section has 12 facets that border the girdle portion of the longitudinal half section. 
    
    
     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 of FIG. 1; 
     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 gemstone illustrated in FIG. 1, and the facets provided on the crown; 
     FIG. 5 shows an enlarged side view of an exemplary embodiment of the gemstone according to the present invention; 
     FIG. 6 shows a side view of different portions of the gemstone of FIG. 5; 
     FIG. 7 shows an enlarged bottom view of the gemstone illustrated in FIG. 5; 
     FIG. 8 shows an enlarged top view of the gemstone illustrated in FIG. 5; 
     FIG. 9 shows a top view of exemplary facets of the gemstone according to the present invention; and 
     FIG. 10 shows a side view of the gemstone illustrated in FIG. 5 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. 5-10. FIG. 5 shows an enlarged side view of the gemstone  200  which has a round shape as viewed from top or bottom views (e.g., see FIGS.  8  and  9 ). However, it is possible that another embodiment of the gemstone of  200  of the present invention may have other shapes (e.g., an oval shape, a marquis shape, etc.). 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. 5 and 6 includes a crown  220 , a pavilion  230 , a girdle  240 , and particular facets provided on the crown  220 . An enlarged bottom view of the pavilion  230  is shown in FIG. 7, and an enlarged top view of the crown is shown in FIG.  8 . The crown  220  is provided above the pavilion  230 , and is separated from the pavilion  230  by the girdle  240 . The crown  220  has a table  350  and facets provided thereon. The facets are defined by a substantially straight edges. However, for the facets that border the girdle  240 , at least one the such edges are not necessarily extend in a straight line. It is preferable that these edges have a curved shape so as to form a curved (e.g., round or oval) edge of the girdle  240 . 
     The facets of the crown  220  preferably include are eight star facets  310 , and eight upper main facets  320 . According to the present invention, further facets are provided on the crown  220  of the gemstone  200 . As described above, the conventional gemstone  10  includes eight left-side upper girdle facets  130  and eight right-side upper girdle facets  140  that are provided or produced on the crown  20 . In contrast, the crown  220  of the gemstone  200  according to the present invention has eight left-side partial girdle facets  360 , eight right-side partial girdle facets  370  and eight middle girdle facets  380 . Thus, the total number of facets provided or created on the crown  220  of the gemstone  200  is  40  (not including the table  350 ). Therefore, according to the above-described exemplary embodiment of the present invention, the crown  220  of the gemstone  200  has eight (8) extra facets thereon. These eight additional facets  360 ,  370 ,  380  provide a better effect on the scintillation, which is caused by a light reflection of the light within the gemstone  200 . The pavilion  230  includes twenty-four (24) facets, which is the same number of pavilion facets provided on the conventional gemstone  10 . Accordingly, the total number of facets provided on the gemstone  200  according to the present invention is sixty-five (65), which includes the table  350  as one of the facets. 
     It should be noted that the facets  360 ,  370 ,  380  can be provided or produced by cutting particular sections of the crown  20  of the conventional gemstone  10  and possibly certain sections of the girdle  40 . Each of the sections of the crown  20  to be cut is provided between one respective left-side upper girdle facet  130  and one respective right-side upper girdle facet  140 . In addition, each of the sections of the girdle  40  to be cut borders the bottom edge  138  of the respective left-side upper girdle facet  130  and the bottom edge  148  of the respective right-side upper girdle facet  140 . These sections are preferably cut so that the portions of the respective left-side and right-side upper girdle facets  130 ,  140  are substantially equal. Thus, the surface areas of the facets  360 ,  370  should also be substantially the same. By providing eight additional facets on the gemstone  200  of the present invention, it is possible to obtain a better brilliance of the gemstone, while losing only 2% (approximately) of the gemstone&#39;s carat weight. 
     In this manner, it is possible to form the facets  360 ,  370 ,  380  of the crown  220  of the gemstone  200  shown in FIGS. 5 and 6. It is also possible to cut the facets  360 ,  370 ,  380  without first creating the left-side and right-side upper girdle facets  130 , 140  by making or cutting each of the facets  360 ,  370 ,  380  separately. It should be understood that the above-described sections of the gemstone  10  are cut in a matter that is well known to those having ordinary skill in the art. 
     FIG. 8 shows an enlarged top view of the gemstone  200  according to the present invention, and FIG. 9 shows an exploded top view of the table  350  and the facets  310 ,  320 ,  360 ,  370 ,  380  of the gemstone  200 . In particular, the longest edges  315  of the star facets  310  form edges  355  of the table  350 . A right edge  318  of each star facet  310  forms a shorter left edge  326  of a respective upper main facet  320 . A left edge  317  of each star facet  310  forms a shorter left edge  328  of another upper main facet  320 . A left-side edge  366  of each partial left-side upper girdle facet  360  forms a longer right edge  322  of a respective upper main facet  320 . A right-side edge  372  of each partial right-side upper girdle facet  370  forms a longer left edge  324  of another upper main facet  320 . 
     A short right-side edge  364  of each partial left-side upper girdle facet  360  contacts a short left-side edge  374  of the respective partial right-side upper girdle facet  370 . A left edge  384  of each middle girdle facet  380  contacts a long right-side edge  362  of the respective partial left-side upper girdle facet  360 , and a right edge  382  of the same middle girdle facet  380  contacts a long left-side edge  376  of another one of the partial right-side upper girdle facets  370 . Bottom edges  368 ,  378 ,  388  of the upper girdle facets  360 ,  370 ,  380  collectively form an upper edge  243  of the girdle  240 . 
     To further explain the gemstone  200  of the present invention, the gemstone  200  can be conceptually subdivided into eight longitudinally-extending sections  510 - 580 , as shown in FIG.  10 . In particular and when viewed from above, each section of the gemstone  200  includes at least one partial left-side upper girdle facet  360 , at least one partial right-side upper girdle facet  370  and at least one middle girdle facet  380 . Thus, at least three facets  360 ,  370 ,  380  of each section have edges that border the girdle  240 . According to the present invention, it is also conceivable that each of the sections  510 - 580  has other facets that border the girdle (e.g., preferably up to five facets in total). In addition, each section preferably includes at least one star facet  310 . 
     FIG. 10 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 φ of the girdle  240  of the gemstone  200  is set at 100%, and extends in a direction A along the diameter φ. As such, the diameter φ of the girdle  240  shall serve for the description below as a reference size 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 37.5° as measured with respect to the diameter φ of the girdle  240 . A diagonal side  235  of the pavilion  230  may extend at a pavilion angle α of approximately 39.6° and 42.2° as measured with respect to the diameter φ of the girdle  240 . Each middle girdle facet  380  is provided at a facet angle which is between approximately 43.7° and 50.7° as measured with respect to the direction A. 
     A width φ 1  of the table  350  is approximately 53% to 66% in comparison with the diameter φ 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 φ of the girdle  240 . The girdle  240  has a girdle thickness a of approximately 2% to 4.5% in a relative comparison with the diameter φ 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 41.5% to 45% compared to the diameter φ of the girdle  240 . A total height T d  of the gemstone  200  (measured from the table  350  to the pointed portion  238  of the pavilion  230 ) may be approximately 55.5% to 63.9% compared to the diameter φ of the girdle  240 . 
     As an example, if the gemstone  200  has a carat weight of 2.5 carats, the diameter φ of the girdle  240  may be 10 mm. Accordingly, the table width φ 1  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 0.45 mm, the pavilion height h p  can be between 4.15 mm and 4.5 mm, and the total height T d  is preferably between 5.55 mm and 6.39. 
     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.