Abstract:
The present invention discloses a round brilliant cut diamond. The diamond includes a crown, a girdle, and a pavilion, the cut crown includes one regular octagon table, eight first facets, eight second facets, and sixteen third facets, wherein the cut pavilion has sixteen quadrangular fourth facets, sixteen quadrangular fifth facets, and sixteen sub-triangular sixth facets. The sixteen fourth facets meet at a point, which forms an apex, and each fourth facet, fifth facet and sixth facet meet a point. The present invention also discloses methods for preparing above mentioned round brilliant-cut diamond.

Description:
BACKGROUND OF THE PRESENT INVENTION 
       [0001]    1. Field of Invention 
         [0002]    The present invention relates to diamond cutting method, and more particularly, relates to a kind of round brilliant cut diamond as well as the method for preparing thereof. 
         [0003]    2. Description of Related Arts 
         [0004]    Round brilliant cut diamond, also known as standard brilliant cut diamond, is the hottest style available in current market. Ordinarily, a standard round brilliant-cut diamond comprises a crown portion, a girdle portion and a pavilion portion for defining total 57 facets thereon, wherein the crown portion has a table facet and three set of crown facets with a total of 33 facets, the pavilion portion has two set of pavilion facets with a total of 24 facets. Actually, the girdle portion is embodied as a cylinder shape. The reason why such type of diamond is referred as round brilliant diamond could be attributed to such cylinder shape girdle portion. That is to say, the cross section of the girdle of the diamond is round shape. As shown in  FIG. 1 ,  FIG. 2  and  FIG. 3 , a round brilliant-cut diamond comprises a crown portion  91 , a girdle portion  92  and a pavilion portion  93  for defining 57 facets, wherein the crown portion  91  has a octagonal table facet, eight first facets  912 , eight second facets  913 , sixteen third facets  914 , eight fourth facets provided onto the pavilion portion  92 , and sixteen fifth facets  932 . 
         [0005]    The brilliancy, dispersion and flickering of the diamond are varied by its cut. That is to say, the quality of the diamond is not only determined by its intrinsic property, such as the size of the raw stone, the light reflection rate and so on, but also depended on the cutting craftwork. In other words, the brilliancy and dispersion of the diamond is achieved by cutting the diamond into a plurality of evenly distributed facets. The size and shape of such facets will be the key factor attributed to a fine diamond. A well defined cut will increase the visual-perceptible reflection of light ray thus improving the brilliancy whenever such diamond is observed by a user. It is therefore seen stricter orders and procedures have been introduced within the art instructing people to cut the diamond. 
         [0006]    However, the conventional 57 facets cutting method is not desirable for preparing a relatively larger raw stone. The brilliance and flickering effect would be look inanimate and uncharacteristic. On the other hand, the arrangement and orienting angle setting of the facets are also important to achieve desirable physical reflection rays. 
       SUMMARY OF THE PRESENT INVENTION 
       [0007]    A primary object of the present invention is to provide a diamond cutting method for not only increasing the quantity of facets, but also perfecting the relative angles, size and arrangement of such facets, therefore, the diamond prepared in present invention will be observed with improved brilliancy and ray dispersion. 
         [0008]    Another object of the present invention is to provide a diamond cutting method for increasing facets on the pavilion portion of the diamond, namely 3-5 sets of facets on the pavilion portion, wherein the newly added facets are harmonized with crown portion facets so as to reinforce the internal flickering, ray dispersion and overall brilliance of the diamond. 
         [0009]    Accordingly, to achieve above object, the present invention provides a cutting method for cutting at least 3-5 set of pavilion facets for substantially exhibiting the flickering, dispersion and brilliancy of the diamond. 
         [0010]    These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is a top view of a standard 57 facets round brilliant-cut diamond. 
           [0012]      FIG. 2  is a side view of a standard 57 facets round brilliant-cut diamond. 
           [0013]      FIG. 3  is a bottom view of a standard 57 facets round brilliant-cut diamond. 
           [0014]      FIG. 4  is a side view of a round brilliant-cut diamond according to a preferred embodiment of the present invention. 
           [0015]      FIG. 5  is a bottom view of above round brilliant-cut diamond according to the preferred embodiment of the present invention. 
           [0016]      FIG. 6  is a side view of above round brilliant-cut diamond according to a second embodiment of the present invention. 
           [0017]      FIG. 7  is a bottom view of above round brilliant-cut diamond according to the second embodiment of the present invention. 
           [0018]      FIG. 8  is a side view of above round brilliant-cut diamond according to a third embodiment of the present invention. 
           [0019]      FIG. 9  is a bottom view of above round brilliant-cut diamond according to the third embodiment of the present invention. 
           [0020]      FIG. 10  is a side view of above round brilliant-cut diamond according to a fourth embodiment of the present invention. 
           [0021]      FIG. 11  is a bottom view of above round brilliant-cut diamond according to the fourth embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0022]    As shown in  FIG. 1 ,  FIG. 2 , and  FIG. 3 , a conventional standard round brilliant-cut diamond is illustrated, wherein the diamond comprises a crown portion  91  having an octagonal table facet  911 , eight first facets  912 , eight second facets  913 , and sixteen third facets  914 , and a pavilion portion  92  having eight fourth facets  931  and sixteen fifth facets  932 . 
         [0023]    Referring to  FIG. 4  and  FIG. 5 , a round brilliant-cut diamond according to a preferred embodiment of the present invention is illustrated, wherein the diamond comprises a crown portion  1 , a girdle portion  2  and a pavilion portion  3 . Like conventional 57 facets diamond, the crown portion  1  is consisted of three sets of facets, namely, eight first facets  12 , eight second facets  13  and sixteen third facets  14 . According to the preferred embodiment of the present invention, the width of the table facet  11  of the crown portion is proportionally sized with respect to the diameter of the girdle portion  2 , wherein the size ration is ranged from 0.56 to 0.58. The lengths of the first facet  11  and the second facet  12  are prepared with a same size. The pavilion portion  3  comprises sixteen quadrangle shaped fourth facets  31 , sixteen quadrangle shaped fifth facets  32 , and sixteen sub-triangle shaped sixth facets  33 , wherein the sixteen fourth facets  31  are merged into a bottom peak point  35 , each of the correspondingly grouped fourth facet  31 , fifth facet  32  and sixth facet  33  is also merged into a joint point. Preferably, the pavilion angle  36  of the pavilion portion  3  is defined within a range between 40.8° and 41.5°. Furthermore, the length ratio between the sixth facet and the fifth facet is around 0.25. 
         [0024]    The present invention further provides a corresponding method for cutting the diamond of above preferred embodiment. First of all, the crown portion  1  is cut to define a table facet  11 , a plurality of first facets  12 , a plurality of second facets  13 , and a plurality of third facets  14 . Afterwards, the upper edge  36  of the pavilion portion  3  is cut to define sixteen fourth facets  31 . After then, each of the included angles between neighboring fourth facets  31  is cut to define sixteen fifth facets  32 ; finally, each of the included angle between neighboring fifth facets  32  at a position adjacent to the girdle portion  2  is cut to define sixteen facets  33 . 
         [0025]    Referring to  FIG. 6  and  FIG. 7 , the round brilliant-cut diamond prepared according to a second preferred embodiment of the present invention is illustrated. The pavilion  3  comprise sixteen quadrangle shaped fourth facets  31 , sixteen quadrangle shaped fifth facets  32 , sixteen quadrangle sixth facets  33 , and sixteen sub-sector shaped seventh facets  34 , wherein the fourth facets  31  are merged into a bottom peak, each of the correspondingly grouped fourth facet  31 , fifth facet  32  and sixth facet  33  is also merged into a joint point. Preferably, the fourth facet  31  is prepared with a diamond shape. It is noted that a pair of short side edges of the fifth facets  32  are embodied as side edges of neighboring fourth facets  31 . Meanwhile, the remaining two long side edges of the fifth facets  32  are sized twice as the length of the side edges of the fourth facets  31 . And the pavilion angle of the pavilion portion  3  is defined within a range between 40.8° and 41.5°. Furthermore, the length ratio between the table facet width and the diameter of the girdle portion is around 0.56. 
         [0026]    Accordingly, the present invention further provides a corresponding method for cutting the diamond of above second preferred embodiment. First of all, the crown portion  1  is cut to define a table facet  11 , a plurality of first facets  12 , a plurality of second facets  13 , and a plurality of third facets  14 . Afterwards, the upper edge  36  of the pavilion portion  3  is cut to define sixteen fourth facets  31 . After then, each of the included angles between neighboring fourth facets  31  is cut to define sixteen fifth facets  32 ; and each of the included angles between neighboring fifth facets  31  is cut to define sixteen sixth facets  33 . Finally, each of the included angles between neighboring sixth facets  33  at a position adjacent to the girdle portion  2  is cut to define sixteen sub-diamond shaped seventh facets  34 . 
         [0027]    Referring to  FIG. 8  and  FIG. 9 , the round brilliant-cut diamond prepared according to a third preferred embodiment of the present invention is illustrated. The pavilion  3  comprise sixteen quadrangle shaped fourth facets  31 , sixteen quadrangle shaped fifth facets  32 , sixteen quadrangle sixth facets  33 , and a seventh facet  34  defined at the bottom side thereof, wherein the fourth facet  31  and the seventh facet  34  share a common side edge, each of the correspondingly grouped fourth facet  31 , fifth facet  32  and sixth facet  33  is also merged into a joint point. And more importantly, the bottom seventh facet  34  is paralleled with the table facet  11  of the crown portion  1 . 
         [0028]    Or otherwise, referring to  FIG. 10  and  FIG. 11 , the round brilliant-cut diamond prepared according to a fourth preferred embodiment of the present invention is illustrated. The pavilion  3  comprise sixteen quadrangle shaped fourth facets  31 , sixteen quadrangle shaped fifth facets  32 , sixteen quadrangle sixth facets  33 , sixteen sub-sector shaped seventh facets  34 , and a eighth facet defined at the bottom side thereof, wherein the fourth facet  31  and the seventh facet  34  share a common side edge, each of the correspondingly grouped fourth facet  31 , fifth facet  32  and sixth facet  33  is also merged into a joint point, each of the correspondingly grouped fifth facet  32 , sixth facet  33  and seventh facet  34  is merged into a joint point. And preferably, the bottom eighth facet  35  is paralleled with the table facet  11  of the crown portion  1 . 
         [0029]    Regarding to the present invention, the brilliant-cut diamond substantially increases its facets that the total number of facets of the brilliant-cut diamond can be increased to 81, 82, 97, or 98. The array and the size of each of the facets can be selectively adjusted with respect to the diamond in ratio. Accordingly, by increasing the number of facets, the diamond enhances the internal flickering and ray dispersion and increases the value of the diamond. 
         [0030]    One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting. 
         [0031]    It will thus be seen that the objects of the present invention have been fully and effectively accomplished. Its embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure form such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.