Patent Publication Number: US-2021177109-A1

Title: Gemstone settings and setting methods

Description:
BACKGROUND 
     Gemstones such as diamonds are prized for their capacity to sparkle, making them attractive and eye-catching when used in jewelry. In order to maximize their sparkle, gemstones are carefully cut into shapes that are not only attractive but also have facets and angles that reflect the light in an ideal manner. Alternatively, some gemstones may be used in jewelry without cutting and/or without the use of facets, depending on the nature of the stone and aesthetic preferences. Whatever method is used to prepare the gemstone for use in jewelry, the goal is to show the gemstone&#39;s beauty through sparkle, reflection, and/or other appealing attributes. 
     Because of the beauty and rarity of gemstones, many are very expensive. As such, gemstones must be carefully retained in jewelry using strong metal settings. These settings must hold the gemstones securely, even when subject to external pressure as might occur during jewelry wear. At the same time, the settings should augment the appearance of the gemstone, rather than detract from it. 
     There are several gemstone setting techniques which are popular. Gemstones may be held using prongs, for example, in which multiple tines extend from the bottom of the gemstones and around the sides, terminating in claws which hook over the girdle and onto the crown, or upper surface, or the stone. Prong settings leave the gemstone highly visible, but the prongs can become snagged and may bend, creating is a risk that the gemstone could become dislodged and lost. In barrel settings, the gemstone sits within a cup of that wraps around the gemstone, with a barrel, an inward projecting rim extending over the girdle and onto the outer edge of the crown to securely hold the gemstone. The barrel setting method provides a secure hold but obscures a portion of the stone in a manner that may make the gemstone appear smaller. Many other setting methods are also known. However, in each case, the setting must balance the need to securely hold the stone against aesthetic concerns such as showing the stone as fully as possible to maximize its visual appeal. 
     SUMMARY 
     Various embodiments include gemstones, gemstone settings and methods of setting gemstones. In some embodiments, the set gemstone includes a cut gemstone having a girdle having a lower edge and a plurality of horizontal grooves each having an upper edge and a lower edge, wherein the upper edges of the plurality of horizontal grooves are located within the girdle, abut a lower edge of the girdle, or are within 1 millimeter beneath the lower edge of the girdle or within 0.5 millimeters of the lower edge or the girdle. The set gemstone also includes a cylindrical barrel having a central aperture, an open top, a rim at the top forming an upper edge of the barrel, and a plurality of flanges projecting into the central aperture of the barrel located directly beneath the rim, wherein the flanges project into the grooves to maintain the gemstone within the barrel. The gemstone may include an upper portion above the girdle and a lower portion below the girdle, and no portion of the barrel may extends above any of the upper portion of the gemstone such that the upper portion of the gemstone is fully visible. In some embodiments, the barrel may cover only a portion of a width of the girdle such that a remaining portion of the width of the girdle is visible above the rim. 
     In some embodiments, the plurality of grooves may be between 3 and 5 grooves. The grooves may include wedge shaped cuts into the gemstone. The cylindrical barrel may be tapered such that it has a larger inner and or outer diameter at the open top than at a bottom of the cylindrical barrel. 
     In some embodiments, the gemstone may be a brilliant cut gemstone. The brilliant cut gemstone may include a plurality of lower girdle facets and the horizontal grooves may each e centered about a line of abutment between adjacent lower girdle facets. 
     In other embodiments, a method of mounting a gemstone in a barrel setting includes selecting a prepared gemstone including a plurality of horizontal groves in a lower portion of the gemstone, selecting or creating a cylindrical barrel setting comprising a tube having a central aperture and a plurality of horizontal flanges projecting into the aperture, the central aperture sized to fit the gemstone within it, inserting the gemstone into the aperture of the barrel setting with the horizontal grooves aligned with the horizontal flanges, applying pressure to the gemstone to advance it forward into the aperture of the barrel setting such that the lower portion of the gemstone presses against the horizontal flanges to flex them, and releasing pressure on the gemstone once the gemstone has advanced sufficiently for the horizontal flanges to become inserted into the horizontal grooves to set the gemstone. The plurality of horizontal grooves may be located within a girdle of the gemstone, abutting a lower edge of the girdle of the gemstone, or adjacent to a lower edge of a girdle of the gemstone. In some embodiments, the upper edge of the grooves may be located within 0.5 millimeter beneath of a lower edge of the girdle. The plurality of horizontal grooves may be between 3 and 5 horizontal grooves and the plurality of horizontal flanges may likewise be between 3 and 5 horizontal flanges. A portion of or all of the gridle may be visible above the upper edge of the cylindrical barrel. When the gemstone is set within the barrel setting, an entire portion of the gemstone above the girdle may be visible and unobstructed by the barrel setting. The plurality of horizontal grooves may include an upper surface and a lower surface cut into the gemstone forming a wedge having a double pointed oval shape. The gemstone may be a brilliant cut diamond, for example. 
     Other embodiments include a method of preparing a gemstone for mounting in a barrel setting including selecting a gemstone having a brilliant cut with a girdle, and cutting the gemstone to widen the girdle, cutting a plurality of horizontal grooves into the gemstone, the upper edges of the grooves located within the widened girdle, at the lower edge of the widened girdle, or within 1 millimeter of the lower edge of the widened girdle. The methods may further include cutting a plurality of horizontal grooves into the gemstones by cutting the gemstone to form a top surface and cutting the gemstone to form a bottom surface of each groove, wherein the top and bottom surfaces come together as a wedge in a pointed oval shape. The gemstone may include a plurality of lower girdle facets and cutting a plurality of horizontal grooves into the gemstone may include cutting the horizontal grooves into the gemstone at locations centered where adjacent lower girdle facets abut each other. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following drawings are illustrative of embodiments and do not limit the scope of the invention. The drawings are not necessarily to scale and are intended for use in conjunction with the following detailed description. Embodiments of the invention will be described with reference to the drawings, in which like numerals may represent like elements. 
         FIG. 1  is a side view of an example traditionally cut gemstone; 
         FIG. 2  is a side view of an example gemstone modified to have a widened girdle according to various embodiments; 
         FIG. 3 . is a bottom view of the gemstone of  FIG. 2  further modified to include a plurality of grooves according to various embodiments; 
         FIG. 4  is a side view of the gemstone of  FIG. 3 ; 
         FIG. 5  is a perspective view of a barrel setting according to various embodiments in a semi-cross-sectional line drawing; 
         FIG. 6  is a perspective view of the barrel setting of  FIG. 5 ; 
         FIG. 7  is a side view of the gemstone of  FIGS. 3 and 4  mounted into the barrel setting of  FIGS. 5 and 6  in a semi-cross-sectional line drawing; and 
         FIG. 8  is a perspective view of the mounted gemstone of  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description is exemplary in nature and is not intended to limit the scope, applicability, or configuration of the invention. Rather, the following description provides practical illustrations for implementing various exemplary embodiments. Utilizing the teachings provided herein, those skilled in the art may recognize that many of the examples have suitable alternatives that may be utilized. 
     Various inventions described herein include new gemstone settings and new methods for setting gemstones. Faceted gemstones may be used in these methods and the girdle of the gemstones may be carved wider than is typical in other settings. A plurality of horizontal groves may be carved into the gemstone at or near the lower edge of the widened girdle, and these grooves may be used to retain the gemstone within a setting. The setting may be a circular band forming a cup or barrel around the pavilion of the gemstone with a plurality of ridges projecting inward and aligned with the grooves in the gemstone to invisibly hold the gemstone within the cup. Using these settings and methods, the gemstone is securely retained in a manner which enhances its visibility by holding the gemstone without covering the crown or making the stone appear smaller. 
     Any natural, synthetic or artificial gemstone may be used in these inventions. While the inventions may be particularly useful for showcasing precious stones, it may also be used effectively with semiprecious stones or even natural or artificial gemstones of low value. Examples of appropriate stones include but are not limited to diamonds, emeralds, sapphires, rubies, and their synthetic or artificial equivalents such as cubic zirconium, zircon, and moissanite as well as less expensive gemstone looking materials such as crystal or glass. 
     The set gemstones as described herein may be used with any type of jewelry such as rings, earrings, bracelets or necklaces. Alternatively, the set gemstones may be used as decorations on any non-jewelry items such as decorative boxes or other objects. 
     For reference, a typical faceted brilliant round gemstone as is used in prior art settings is shown in  FIG. 1 . The gemstone  10  includes an upper portion which is the crown  12  and a lower portion which is the pavilion  14 . A girdle  16  forms the outermost edge of the gemstone, between the crown  12  and the pavilion  14 . The flat upper surface of the gemstone is the table  18 , and the pointed lower tip is the culet  20 . The facets around the girdle  16  include upper girdle facets  22  and lower girdle facets  24 . Kite facets  26  extend downward from above for form points at the upper edge of the girdle  16  while pavilion main facets  28  extend from below to form points at the lower edge of the girdle  16 . The crown further includes star facets  27  surrounding the table  18 . 
     An example of a gemstone  110  which may be used in various embodiments of the inventions is shown in  FIG. 2 . Like the traditional gemstone  10  shown in  FIG. 1 , the gemstone  110  includes a crown  112 , a pavilion  114 , a table  118 , and a culet  120 . The gemstone  110  also includes a girdle  116 . It further includes the upper and lower girdle facets  122 ,  124 , kite facets  126 , pavilion main facets  128 , and star facets  127 . However, as shown in the figures, the girdle  116  of the gemstone  110  according to the various embodiments is wider than the girdle  16  of a traditionally cut gemstone. 
     While the girdle  116  is wider than that of a traditionally cut gemstone, the actual width used for a particular gemstone will vary depending upon the size and dimensions of the gemstone  110 . As can also be seen in  FIG. 2 , the width of the girdle  116  is not uniform around the gemstone  110  but rather is slightly wider where the gemstone  110  is widest, namely where the edges of the upper and lower girdle facets abut each other along their vertical edges and at the points and where the tips of the kite facets  126  and the pavilion main facets  128  meet, and is slightly narrower between these points (that is, extending between the edges of the facets). This variation in width is due to the faceted nature of the gemstone. Thus, the widened girdle  116  varies slightly in width in a symmetrical and uniform nature around the circumference of the gemstone  110 . 
     The width of the widened girdle, and the amount by which it may be widened, varies depending upon the characteristics of the gemstone itself. As such, the width of the widened girdle, taken at either its widest or narrowest location, for example, may be considered relative to the dimensions of the particular gemstone, such as the diameter of the gemstone after it is cut with the widened girdle, rather than as an absolute value. For example, in some embodiments, the width of the widened girdle may be between approximately 20% and approximately 5% of the diameter of the gemstone. In other embodiments, the width of the widened girdle may be between approximately 10% and approximately 15% of the diameter of the gemstone. In still other embodiments, the width of the widened girdle may be between approximately 12%-13% of the diameter of the gemstone. 
     In addition to having a widened girdle  116 , the gemstone  110  may be further modified to include a series of grooves  130  as shown in  FIGS. 3 and 4 . In  FIG. 3 , the gemstone  110  is shown from below, while in  FIG. 4  it is shown in a lateral perspective. In this example, there are four grooves  130 , though in other embodiments fewer or greater numbers of grooves could be used, such as 2, 3, 5, 6, or 8. 
     The grooves  130  may be located directly below the widened girdle  116 . In the examples shown in  FIGS. 3 and 4 , the grooves  130  have a double pointed oval shape or and include an upper surface  132 , a lower surface  134  and a pair of ends  136  where the fronts of the upper and lower surfaces  132   134  meet. In other examples, other groove shapes are possible, such as an oval with rounded ends, rectangular, etc. 
     The grooves  130  may be located in close proximity to the lower edge of the widened girdle. For example, the grooves  130  may be spaced very slightly beneath the lower edge of the widened girdle  116 , such as touching or virtually touching the lower edge of the widened girdles, such as less than or equal to about 1 mm or less than or equal to about 0.5 mm from the lower edge or the girdle  116 . In other embodiments, the upper surfaces  132  of the grooves  130  may abut or may approximately abut the lower edge of the girdle  116 . In still other embodiments, the upper surfaces  132  of the grooves  130  may overlap and partially impinge upon the girdle  116 . An example of such an embodiment is shown in  FIG. 3 , in which the front of the upper surfaces  132  of the grooves  130  slightly overlap the lower portion of the widened girdle  116 , effectively narrowing the girdle  116  slightly at those locations. The choice of precise location of the grooves  130  relative to the girdle  116  may vary depending upon the size and dimensions of the gemstone  100 , the design and nature of the ultimate setting or jewelry piece, and personal preference. 
     The grooves  130  may be placed at locations where two adjacent lower girdle facets  124  abut each other side by side and may be aligned approximately symmetrically about this line of abutment. For example, as shown in  FIG. 4 , the grooves  130  are symmetrical about each vertical line of abutment between adjacent lower girdle facets  124 . In this example, the grooves  130  extend horizontally across the majority of the width of each of adjacent lower girdle facet  124  and end at ends  136  before the opposite edge of the facets  124  before the upper tips of the pavilion main facets  128 . However, in other embodiments the grooves  130  may extend horizontally across less than a majority of the width of the adjacent lower girdle facets  124  or may extend up to the edge or beyond the other edge of each of the adjacent lower girdle facets  124 . As such, the width of the grooves  116  may vary among different stones depending upon the choice of the jeweler in how wide to extend the grooves  130  as well as the size of the gemstone. For example, the groove  116  width, depth and location may vary depending upon the gemstone characteristics, such as its size. In some embodiments, a first groove  116  may be placed at a first location, with the location of the remainder of the grooves  116  dependent upon the location of the first groove  116 . For example, in an embodiment including 4 grooves  116 , once the first grove  116  is placed it may be considered the 12 o&#39;clock location, with the other groves subsequently placed in any order at evenly spaced locations at the 3, 6, and 9 o&#39;clock locations. 
     The depth of the grooves  130  are adequate to securely hold the gemstone  110  within the barrel  200 . For example, the grooves  130  may have a maximum depth at their center. However, the actual depth may vary depending upon the dimensions of the particular gemstone. As such, the depth may be considered relative to the diameter of the gemstone. In some embodiments, the maximum depth may be between about 10% and about 20% of the diameter of the gemstone, for example. In other embodiments, the maximum depth may be between about 10% and about 15% of the diameter of the gemstone. 
     When fitting the prepared gemstone  100  into a setting, a barrel  200  may be selected which is appropriately sized to fit the gemstone. An example of a barrel which may be used in various embodiments is shown in  FIGS. 5 and 6 . The barrel  200  includes a cylindrical sidewall  202  that may taper slightly outward at the top as shown or may alternatively be more tapered or may be straight. The barrel  200  may be open at the top and the bottom, though in alternative embodiments it may be closed at the bottom if desired. The sidewall  202  may include an interior surface  204  and an exterior surface  205 . While the exterior surface  205  may be a continuous smooth curved plane throughout, the interior surface  204  may angle outward near the top to form a ledge  206  to accommodate the outer aspect of the pavilion of the gemstone in a nesting fashion or an approximately or nearly nesting fashion. Above the ledge  206 , a plurality of flanges  210  may project inward for holding the gemstone  100  after it is placed in the barrel  200 . The plurality of flanges  210 , in this example four, may be sized and spaced and located on the barrel  200  such that they align with the grooves  130  of the gemstone  100  when it is fitted into the barrel  200 . The barrel  200  may further include a rim  214  projecting upward above the flanges  210  forming the top of the barrel. The rim  214  may be sized to fit the girdle  116  of the gemstone  100 , with a height that extends partially or fully up the width of the girdle  116 . As such, the height of the rim  214  may be less than, equal to, or greater than the width of the girdle  116  to partially or fully cover the girdle  116 , depending upon the preference for the final look of the seated gemstone  100 . In examples in which the height of the rim  214  is less than the width of the girdle, the gemstone  200  may be less obstructed by the setting and may appear larger and more prominent. 
       FIGS. 7 and 8  show the gemstone  110  securely seated in the barrel  200 . In this example, the rim  214  of the barrel  200  covers most of the girdle  116  of the gemstone  110 , with a small amount of the girdle  116  visible above the rim  214 . The flanges  210  have been inserted into the grooves  132 , and the rigidity of the flanges  210  hold the gemstone  110  within the barrel  200 . 
     As can be appreciated in  FIGS. 7 and 8 , no portion of the barrel covers any part of the crown  112  of the gemstone  110 . As such, with entire crown  112  visible, the gemstone  110  appears larger, more visible, and more attractive than other barrel settings in which a circumferential rim covers the outer edge of the top of the gemstone. 
     In practice, a gemstone may be mounted according to various embodiments beginning with either a cut gemstone or an uncut gemstone. If the gemstone has already been cut into a traditional brilliant cut design, the cut gemstone may then be modified to include a widened girdle using an appropriate gem cutting tool such as a diamond bruiting machine. If the gemstone is not in a final cut form, it may first be cut into a traditional brilliant cut and then the girdle may be widened as described above. Alternatively, the gemstone may be cut into a modified brilliant cut having a widened girdle as part of the gemstone cutting process. 
     Once the gemstone has been prepared with a widened girdle, grooves may be cut into the stone immediately beneath the girdle. Again, standard gem cuttings tools may be used, such as a diamond coated ceramic blade. In some examples, a pair of horizontal cuts may be made, including an upper cut to form the upper surface  132  and the lower cut to form the lower surface  134 . These two cuts may angle toward each other, coming together at the back of the grove  130 , to form a wedge shaped groove  1   30  having the desired depth. In some embodiments, the plane of the upper edge  132  may be horizontal or approximately horizontal, while the lower edge  134  may be angled upward. Other shapes and angles are also possible and may be designed to match the shape of the flange with which it is to be used. For example, in the embodiments shown, the grooves  130  is a wedge-shaped space while the flanges  210  are wedge shaped to fit within the grooves  130 . 
     The barrel  200  may be created using a mold sized and shaped to create a barrel  200  according to various embodiments. For example, a molten alloy may be used to create the barrel  200  using a casting process and a mold such as a rubber mold. A plurality of barrels  200  having a range of sizes may be prepared in advance, such that the size of the prepared gemstone  100  may be measured and/or visually compared to the barrels  200  to pick one of the appropriate size. For example, after the gemstone  100  is prepared as described above, the size of the prepared gemstone  100  may be measured and/or visually compared to the upper opening of one or more barrels  200  to determine which would be the best fit. The barrel  200  having the opening within the upper opening surrounded by the barrel rim  214  which is the smallest but which still accommodates the gemstone  100  may be the best fit to avoid a gap between the gemstone and the barrel rim  214 . Alternatively, the gemstone  100  may be prepared as described herein and the barrel  200  may then be prepared accordingly, with the appropriate sized mold selected based upon the size of the prepared gemstone  100 . 
     Once the gemstone  100  has been prepared and the barrel  200  created and/or selected, the gemstone  100  may be mounted within the barrel  200 . The flanges  210  of the barrel  200  may be rigid but may have a small ability to flex. As such, the gemstone  100  may be mounted by placing it into the barrel  100  from above. At this point, the pavilion  114  may be resting upon the top of flanges  210 , with each groove  130  located directly above a flange  210 . The gemstone  100  may then be pushed downward, causing the flanges  210  to flex slightly downward. Once the gemstone  100  has advanced sufficiently into the barrel  200 , the grooves  130  may then horizontally align with the flanges  210 , such that the flanges  210  spring upward into the spaces of the grooves  130 . Once this happens, pressure is released and the gemstone  100  is then held in place in the barrel  200  by the flanges  210  projecting into each groove  130 . 
     A gemstone  100  set into a barrel setting  200  according to various embodiments may be set into a jewelry piece or other object. Alternatively, the barrel  200  may be set into a jewelry piece or other object prior to setting the gemstone  100  in the barrel  200 . 
     In the foregoing description, the inventions have been described with reference to specific embodiments. However, it may be understood that various modifications and changes may be made without departing from the scope of the inventions.