Abstract:
The instant application discloses, among other things, a specific set of cutting proportions tailored for the optical characteristics of Silicon Carbide (“SiC”) cushion-cut gemstone which may produce a “Hearts &amp; Arrows” reflection pattern.

Description:
FIELD 
       [0001]    This disclosure relates to a way to produce a “Hearts &amp; Arrows” reflection pattern in a transparent Cushion-Cut Silicon Carbide (“SiC”) gemstone. 
       BACKGROUND 
       [0002]    Generally, facets on precious and semi-precious gemstones are cut so as to provide brilliance to these gemstones in an economical manner. Gemstones may also be cut to provide reflections with patterns visible. 
       SUMMARY OF THE INVENTION 
       [0003]    The instant application discloses, among other things, a specific set of cutting proportions tailored for the optical characteristics of Silicon Carbide (“SiC”) cushion-cut gemstone, which may produce a “Hearts &amp; Arrows” reflection pattern. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]      FIG. 1  is a side view of an example of an SiC cushion-cut gemstone cut with a Hearts &amp; Arrows pattern. 
           [0005]      FIG. 2  is a top view of an example of an SiC cushion-cut gemstone cut with a Hearts &amp; Arrows pattern. 
           [0006]      FIG. 3  is a bottom view of an example of an SiC cushion-cut gemstone cut with a Hearts &amp; Arrows pattern. 
           [0007]      FIG. 4  is an illustration of a flowchart of one way to create an SiC cushion-cut gemstone with a Hearts &amp; Arrows pattern. 
           [0008]      FIG. 5  is an illustration of a bottom view an SiC cushion-cut gemstone with a Hearts &amp; Arrows pattern. 
           [0009]      FIG. 6  is an illustration of a top view an SiC gemstone with a Hearts &amp; Arrows pattern. 
       
    
    
     DESCRIPTION OF THE INVENTION 
       [0010]    Silicon Carbide (SiC) is a compound of silicon and carbon. It exists in a number of crystalline forms, often grouped as polytypes of similar structures. Three common polytypes are 3C (β), 4H, and 6H (α). 3C (β) has a cubic crystal structure; 4H and 6H (α) each have hexagonal crystal structures. 
         [0011]      FIG. 1  is a side view of an example of an SiC cushion-cut gemstone with a Hearts &amp; Arrows pattern. Crown  130  is the portion of a gem above the girdle. Crown  130  has Star Facets  210 , Crown Girdle Facets  220 , Crown Girdle Facets  225 , Crown Bezel Facets  230 , and Crown Bezel Facets  235 . Girdle  130  is the outer edge of the gemstone, separating the Crown  100  and the Pavilion  110 . Girdle  130  is generally located near the area of a gemstone at the widest portion of the gemstone, where Diameter  120  indicates the edge-to-edge width of the gemstone. Table  140  is the largest facet on the gemstone. 
         [0012]      FIG. 2  is a top view (Crown side) of an example of an SiC cushion-cut gemstone with a Hearts and Arrows pattern. The SiC gemstone has a four-fold symmetry. The angles for this cut may be: 
         [0000]    
       
         
               
               
               
             
           
               
                   
                   
               
               
                   
                 Facet 
                 Degrees 
               
               
                   
                   
               
             
             
               
                   
                 Star Facets 210 
                 18.2 
               
               
                   
                 Crown Girdle Facets 220 
                 39.1 
               
               
                   
                 Crown Girdle Facets 225 
                 37.1 
               
               
                   
                 Crown Bezel Facets 230 
                 32.2 
               
               
                   
                 Crown Bezel Facets 235 
                 29.7 
               
               
                   
                   
               
             
          
         
       
     
         [0013]      FIG. 3  is a bottom view (Pavilion side) of an example of an SiC cushion-cut gemstone with a Hearts &amp; Arrows pattern. The angles for this cut may be: 
         [0000]    
       
         
               
               
               
             
           
               
                   
                   
               
               
                   
                 Facet 
                 Degrees 
               
               
                   
                   
               
             
             
               
                   
                 Pavilion Main Facets 310 
                 40.6 
               
               
                   
                 Pavilion Main Facets 315 
                 40.8 
               
               
                   
                 Pavilion Girdle Facets 320 
                 59.5 
               
               
                   
                 Pavilion Girdle Facets 325 
                 58.6 
               
               
                   
                 Lower Halves 330 
                 41.9 
               
               
                   
                   
               
             
          
         
       
     
         [0014]    An SiC cushion-cut gemstone with the angles indicated may display a Hearts &amp; Arrows pattern. One having skill in the art will recognize that slight variations, up to 0.1 degrees greater or smaller, in the cutting angle may still produce the Hearts &amp; Arrows pattern. 
         [0015]      FIG. 4  is an illustration of a flowchart of one way to create a Hearts &amp; Arrows pattern on a Sic cushion-cut gemstone. In this example, a girdle outline is cut  400  to provide a diameter of the SiC gemstone. The pavilion facets are cut  410 , including pavilion main facets and pavilion girdle facets. 
         [0016]    The pavilion facets are polished  420 , as is the girdle  430 . The stone is transferred to allow cutting and polishing of the crown side. 
         [0017]    The crown bezel, star, and girdle facets are cut  450 , and polished  460 . 
         [0018]      FIG. 5  is an illustration of a bottom view a SiC cushion-cut gemstone with a Hearts &amp; Arrows pattern. The Arrows  510  may be a desired design for an SiC gemstone. To reduce clutter in this figure, only two of the eight Arrows  510  are identified. 
         [0019]      FIG. 6  is an illustration of a top view a SiC cushion cut gemstone with a Hearts &amp; Arrows pattern. The Hearts  610  may be a desired design for an SiC gemstone. To reduce clutter in this figure, only two of the eight Hearts  610  are identified. 
         [0020]    While the detailed description above has been expressed in terms of specific examples, those skilled in the art will appreciate that many other configurations could be used. Accordingly, it will be appreciated that various equivalent modifications of the above-described embodiments may be made without departing from the spirit and scope of the invention. 
         [0021]    Additionally, the illustrated operations in the description show certain events occurring in a certain order. In alternative embodiments, certain operations may be performed in a different order, modified or removed. Moreover, steps may be added to the above described logic and still conform to the described embodiments. Further, operations described herein may occur sequentially or certain operations may be processed in parallel. Yet further, operations may be performed by a single processing unit or by distributed processing units. 
         [0022]    The foregoing description of various embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. It is intended that the scope of the invention be limited not by this detailed description, but rather by the claims appended hereto. The above specification, examples and data provide a complete description of the manufacture and use of the invention. Since many embodiments of the invention can be made without departing from the spirit and scope of the invention, the invention resides in the claims hereinafter appended.