DIAMOND CUT

Abstract

A new method of cutting a gemstone such as a diamond, known as the “Galush” cut, is provided. According to an embodiment of the invention, the “Galush” cut gemstone has a crown portion, a pavilion portion and a girdle portion provided between the crown portion and pavilion portion. The crown portion includes an upper surface having a shape configured by first, second and third boundaries, which form a perimeter around the crown of the gemstone. Each of the first and second boundaries has first and second ends, and the third boundary is arc-shaped having first and second edges. The first and second edges of the arc-shaped boundary adjoin the first end of each of the first and second boundaries and the second end of each of the first and second boundaries meet at a common tip.

Description

FIELD OF THE INVENTION

The present invention relates to a new cut and structure for gem stones such as diamonds.

BACKGROUND OF THE INVENTION

The value of a diamond is determined by several parameters including clarity, weight, shape, color, and polish. The cut of the gemstone is generally chosen to maximize the fire of the diamond.

However, in order to produce a brilliant cut diamond having good reflection and refraction (light dispersion), a relative large amount of the diamond raw material is wasted. Currently, 50%-80% of a diamond is wasted during the cutting process. Thus in order to obtain a one carat stone, it is not unusual for the diamond cutter to start with a rough stone weighing 1.7 carat, for example. Since the price per carat increases exponentially in proportion to the carat weight, it is highly desirable to reduce the waste and increase the yield from a rough stone.

Yields may be increased during the faceting process by expert cutting which attempts to achieve a high quality light dispersion while retaining more of the rough stone. Previously, the traditional practice was to limit the angle of the base facets to less than 43% to obtain an acceptable reflection and refraction, which limited the potential saving and the consequent increase in yield.

Various attempts have been made to increase the diamond yield, such as utilizing a greater table spread (the ratio of the table diameter to the girdle diameter). However, the quality and fire of the stone suffered. Other attempts include a mixed-cut square gemstone having a two-step crown, a girdle, and a pavilion (U.S. Pat. No. 5,970,744 to Greeff) and a diamond having a pavilion formed of seventy-two facets and a total of one hundred and six overall (U.S. Pat. Nos. 3,286,486 and 3,585,764 to Huisman et al). However, since many of the facets are added after the bottom pavilion facets have already been cut, there is in fact no improvement in yield.

SUMMARY OF THE INVENTION

The present invention provides a new way of cutting gemstones and diamonds, which provides diamonds with a brilliance comparable with and even greater than conventional or hybrid diamonds and which produce a better yield than conventional cut diamonds. The new cut known as the “Galush” cuts provides an improved yield of approximately 30% compared with conventional diamond cuts. The “Galush” cut is applicable to diamonds and other stones especially round stones.

There is thus provided, according to an embodiment of the invention, a gemstone having a crown portion, a pavilion portion and a girdle portion provided between the crown portion and pavilion portion. The crown portion includes an upper surface having a shape configured by first, second and third boundaries, which form a perimeter around the crown of the gemstone. Each of the first and second boundaries has first and second ends, and the third boundary is arc-shaped having first and second edges. The first and second edges of the arc-shaped boundary adjoin the first end of each of the first and second boundaries and the second end of each of the first and second boundaries meet at a common tip.

Furthermore, according to an embodiment of the invention, the crown portion further includes a plurality of facets formed from a plurality of edges, each edge adjoining two other edges around the perimeter. The number of edges may be an odd number. The number of edges may be a minimum of five edges.

Furthermore, according to an embodiment of the invention, the plurality of facets may include substantially rhomboidal facets.

Furthermore, according to an embodiment of the invention, the crown portion further may include a plurality of secondary star facets.

Additionally, according to an embodiment of the invention, the pavilion portion may include a plurality of facets formed from a plurality of edges, each edge having a common end. The number of edges may be an odd number. The number of edges may be a minimum of five edges.

Furthermore, according to an embodiment of the invention, the wherein the plurality of facets may form a substantially 5-pointed star shape or a substantially 7-pointed star shape.

Furthermore, according to an embodiment of the invention, the pavilion portion may include substantially rhomboidal facets.

Furthermore, according to an embodiment of the invention, the pavilion portion further may include a culet base and a plurality of facets extending from the culet base to the girdle portion. The plurality of star facets may form a substantially four-pointed star shape. Alternatively, the plurality of facets may form a substantially triangular shape.

In addition, there is also provided, according to an embodiment of the invention, a method for cutting a gemstone. The gemstone may include a crown portion, a pavilion portion and a girdle portion provided between the crown portion and pavilion portion. The method may include the step of:

• • configuring the perimeter of the crown of the gemstone in a shape having first, second and third boundaries, each of the first and second boundaries having a first and second ends, and the third boundary being arc-shaped having and having first and second edges.

The first and second edges of the arc-shaped boundary adjoin the first end of each of the first and second boundaries and the second end of each of the first and second boundaries meet at a common tip, the first, second and third boundaries forming the perimeter.

Furthermore, according to an embodiment of the invention, the method may further include the steps of:

• • forming a first plurality of edges on the crown of the gemstone, each of the first plurality of edges adjoining two other of the first plurality of edges; and
  • forming a second plurality of edges on the pavilion of the gemstone, each of the second plurality of edges adjoining two other of the second plurality of edges.

Furthermore, according to an embodiment of the invention, the first plurality of edges may include an odd number of edges. The number of edges may be an odd number. The number of edges may be a minimum of five edges.

Furthermore, according to an embodiment of the invention, the method may further comprise the step of forming a plurality of facets cut from the first plurality of edges.

Furthermore, according to an embodiment of the invention, the method may further comprise the step of forming a plurality of secondary star facets.

Furthermore, according to an embodiment of the invention, the method may further comprise the step of forming a plurality of facets cut from the second plurality of edges, wherein each edge has a common end. The plurality of facets may form a substantially 5-pointed or 7-pointed star shape.

Furthermore, according to an embodiment of the invention, the plurality of facets may include substantially rhomboidal facets.

Furthermore, according to an embodiment of the invention, the pavilion portion further may include a culet base and the method may further include the step of forming a plurality of facets extending from the culet base to the girdle portion. The plurality of star facets may form a substantially four-pointed star shape or alternatively a substantially triangular shape.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding, the invention will now be described, by way of example only, with reference to the accompanying drawings in which like numerals designate like components throughout the application, and in which:

FIGS. 1A-1F are schematic illustrations, showing the “Galush” cut of a round diamond according to an embodiment of the invention in various stages of cutting;

FIGS. 2A-2F are schematic illustrations, showing the “Galush” cut of a round diamond according to a further embodiment of the invention in various stages of cutting;

FIGS. 3A-3B illustrate a further embodiment of the “Galush” cut diamond according to the invention;

FIG. 4 illustrates a further embodiment of the “Galush” cut diamond according to the invention; and

FIGS. 5A-5C illustrates a further embodiment of the “Galush” cut diamond according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed to a new method of cutting a gemstone which increases the yield while achieving a achieving a brilliance and having light dispersion.

The accepted theory in the gem industry that the optimal angle of the base facets is roughly 41 degrees and that even small deviations from this figure will affect the brilliance of the stone has unduly limited the development of other methods of cutting stones. As described in the inventor's U.S. patent application Ser. No. 10/919,257, cutting the base with fewer pavilions leads to a substantially increase in the yield. Thus, for example, a one carat brilliant cut stone may be produced from a rough stone weighing approximately 1.3-1.4 carat, compared with standard cuts which use a rough stone weighing approximately 1.7 to 2 carats to achieve a one carat stone. As will be appreciated such an improvement in yield (of approximately 30%) is especially significant in the diamond industry, where stones are relatively very expensive.

The inventor has also realized that improvement in yield can be gained by cutting and shaping the stone in a specific manner which also emphasizes the diamond's brilliance. The new cut of the diamond, hereinafter referred to as the “Galush” cut, achieves a greater yield by shaping the stone in a specific. It will be appreciated by persons knowledgeable in the art that though the examples refer to round diamonds the same principles also apply to other shapes and other gemstones.

The present invention is described, by way of example only, to FIGS. 1-5, which illustrate different embodiments of the invention.

Reference is now made to FIGS. 1A-1F, which illustrate the cutting of a round diamond, generally designated 10, using the inventive “Galush” cut for a diamond, according to an embodiment of the invention. The “Galush” cut diamond has an innovative shape which appears to resemble a “sector” of a circle having a tip 2 at one end and an arc at its crown 4. The use of an arc 4 in the “Galush” cut provides an improved yield especially when formed from conventional rough diamonds.

In a first step (FIG. 1A), five edges 12a-12e are cut on the crown 4 of the diamond. In the next stage (FIG. 1B), five edges 14a-14e are cut on the base and a girdle is formed. The five edges 14a-14e may have a common end 15. FIG. 1C illustrates a composite view of the stone showing both the top edges 12a-12e and the bottom edges 14a-14e.

In he following stages illustrated in FIGS. 1D and 1E, the stone is “brilliantized”, that is facets are added. FIG. 1D illustrates the addition of facets 20 and half facets 22 to the crown 4. FIG. 1E illustrates the addition of facets 16, 18 to the base of the stone. Facets 16 may form a substantially 5-pointed star shape, as shown.

The completed stone is shown in FIG. 1F. As will be appreciated by persons knowledgeable in the art, there are various embodiments, comprising a plurality of different combinations of facets and half facets which may be added to a stone.

The main feature of the “Galush” cut diamond is the shape of the finished stone and its brilliance. In prior art diamond cutting, a stone is traditionally cut with an even number of facets, usually a multiple of 4. Thus, the crown of the brilliant-cut traditional diamond may have 16 upper Girdle facets, 8 Star facets and 8 Bezel facets, for example. In contrast to the prior art, the inventive “Galush” cut diamond may comprise an odd number of facets, as illustrated in FIGS. 1A-1F.

As will be appreciated, any number and type of facets may be added to the stone without detracting from the novelty of the “Galush” cut. Reference is now made to FIGS. 2A-2F, which illustrate the cutting of a round diamond, generally designated 50, using the inventive “Galush” cut, according to a further embodiment of the invention.

In the embodiment of FIGS. 2A-2E, the stone has the “Galush” shape, that is having a tip at one end and an arc at its crown, and is cut according to the “Galush” method. In this embodiment, the “Galush” cut diamond also comprises an odd number of main facets, in this case seven facets.

In a first step (FIG. 2A), seven edges 52a-52e are cut on the crown 4 of the diamond. In the next stage (FIG. 2B), seven edges 54a-54e are cut on the base and a girdle is formed. FIG. 2C illustrates a composite view of the stone showing both the top edges 52a-52e and the bottom edges 54a-54e.

In he following stages illustrated in FIGS. 2D and 2E, the stone is “brilliantized”, with the addition of facets 60 and half facets 62 to the crown. FIG. 2E illustrates the addition of facets 56 and half facets 58 to the base of the stone. The completed stone is shown in FIG. 2F and comprises a substantially 7-pointed star shape.

A further embodiment of the “Galush” cut diamond is shown in FIGS. 3A and 3B. FIG. 3A illustrates a stone 30 having a “French” culet, as is known in the art, formed on the base of the stone. The facets extending from the culet to the girdle may form a substantially four-pointed star shape 32. The crown may be “brilliantized” with facets and half facets, as previously illustrated, for example, in either FIGS. 1A-1F or FIGS. 2A-2F.

FIG. 3B illustrates the formation of a plurality of facets 36 (“brilliantizing”) on the base of a stone 34 (having a “Galush” shape) which appear to emanate from a common point 38. The plurality of facets 36 form a triangular shape.

In another embodiment shown in FIG. 4, there is illustrated a “Galush” cut diamond, generally designated 40, having seven edges and a plurality of facets. The finished stone comprises a seven-pointed star shape 42 (similar to FIG. 2F).

In another embodiment of the “Galush” diamond, shown in FIGS. 5A-5C, there is illustrated a “Galush” cut diamond, generally designated 60, having a plurality of edges and/or stepped rhomboidal facets 62 formed on the base (FIG. 5A) and a plurality of edges and/or stepped rhomboidal facets 64 formed on the crown (FIG. 5B). The complete diamond is shown in FIG. 5C.

It will be appreciated by persons knowledgeable in the art, that the design possibilities are limitless. It will also be appreciated by persons knowledgeable in the art that variations may be made to the cut of a stone without detracting from the “Galush” cut of the invention. For example, the cut of the stone may be varied by the addition or subtraction of facets and half facets. Furthermore, though the above description relates to a diamond, it will be appreciated that a similar cut may be applied to other gemstones.

Claims

1. A gemstone comprising a crown portion, a pavilion portion and a girdle portion provided between the crown portion and pavilion portion, said crown portion comprising:

an upper surface having a shape configured by first, second and third boundaries, each of said first and second boundaries having a first and second ends, said third boundary being arc-shaped and having first and second edges; and

wherein said first and second edges of the arc-shaped boundary adjoin the first end of each of said first and second boundaries and wherein the second end of each of said first and second boundaries meet at a common tip, wherein said first, second and third boundaries form a perimeter around the gemstone.

2. The gemstone according to claim 1, wherein said crown portion further comprises:

a plurality of facets formed from a plurality edges, each edge adjoining two other edges around the perimeter.

3. The gemstone according to claim 2, wherein said plurality of edges is an odd number of edges.

4. The gemstone according to claim 2, wherein said plurality of facets comprises substantially rhomboidal facets.

5. The gemstone according to claim 2, wherein said crown portion further comprises a plurality of secondary star facets.

6. The gemstone according to claim 1, wherein said pavilion portion comprises a plurality of facets formed from a plurality edges, each edge having a common end.

7. The gemstone according to claim 6, wherein said plurality of edges is an odd number of edges.

8. The gemstone according to claim 6, wherein said wherein said plurality of facets form a shape comprising one of a group of shapes including a substantially five-pointed star or a seven-pointed star.

9. The gemstone according to claim 6, wherein said pavilion portion comprises substantially rhomboidal facets.

10. The gemstone according to claim 2, wherein said pavilion portion further comprises a culet base and a plurality of facets extending from the culet base to the girdle portion.

11. The gemstone according to claim 10, wherein said wherein said plurality of facets form a shape comprising one of a group of shapes including a substantially four-pointed star and a substantially triangular shape.

12. A method for cutting a gemstone, said gemstone comprising a crown portion, a pavilion portion and a girdle portion provided between the crown portion and pavilion portion, the method comprising the steps of:

configuring the perimeter of the crown of the gemstone in a shape comprising a surface having first, second and third boundaries, each of the first and second boundaries having a first and second ends, said third boundary being arc-shaped having and having first and second edges; and

wherein said first and second edges of the arc-shaped boundary adjoin the first end of each of said first and second boundaries and wherein the second end of each of said first and second boundaries meet at a common tip, said first, second and third boundaries forming the perimeter.

13. The method according to claim 12, further comprising the steps of:

forming a first plurality of edges on the crown of the gemstone, each of said first plurality of edges adjoining two other of said first plurality of edges; and

forming a second plurality of edges on the pavilion of the gemstone, each of said second plurality of edges adjoining two other of said second plurality of edges.

14. The method according to claim 13, wherein said first plurality of edges comprises an odd number of edges.

15. The method according to claim 13, further comprising the step of forming a plurality of facets cut from said first plurality of edges.

16. The method according to claim 15, further comprising the step of forming a plurality of secondary star facets.

17. The method according to claim 13, wherein said second plurality of edges comprises an odd number of edges.

18. The method according to claim 17, further comprising the step of forming a plurality of facets cut from said second plurality of edges, wherein each edge has a common end.

19. The method according to claim 18, wherein said wherein said plurality of facets form a shape comprising one of a group of shapes including a substantially five-pointed star or a seven-pointed star.

20. The method according to claim 18, wherein said plurality of facets comprise substantially rhomboidal facets.

21. The method according to claim 13, wherein said pavilion portion further comprises a culet base, the method further comprising the step of forming a plurality of facets extending from the culet base to the girdle portion.

22. The method according to claim 21, wherein said plurality of star facets form a shape comprising one of a group of shapes including a substantially four-pointed star and a substantially triangular shape.