UNIQUELY CUT GEMSTONE WITH A HEART SHAPE AT THE CENTRE AND ITS METHOD OF MANUFACTURE

Abstract

The invention discloses a symmetrically cut gemstone of princess cut (FIG. 1) or cushion cut (FIG. 8) which visually encompassing a heart shape (Z1) within and its method of manufacture. The gemstone has a lower pavilion with a plurality of pavilion facets which emerge upwardly from the culet and are arranged around the pavilion surface on either side of a axis line (C) (FIG. 3, 10). The pavilion facets are symmetrical to the corresponding pavilion facets across the axis. The pavilion facets comprise of triangoid facets (L), chevron facets (M,N) and pavilion main facets, all at specific angles in relation to each other. The pavilion main facet (O) is kite shaped, with short sides (P) converging at the culet, long sides (Q) at 1.sup.st points (R) at a girdle depth of 70 to 86% and the long and short sides at 2.sup.nd points (S) at a girdle depth of 88% to 95%; Pairs of pavilion short half facets (T) are faceted from chevron facets (M,N), and alternate the sides of the pavilion main facets (O) and are formed along a cable (RR) joining the 1.sup.st points. The gemstone is angled at 1st pavilion short half angles (Y) at the girdle depth of 1st point, and are 15 to 30 less than the Triangle main angle (W), and 2 to 9 less than the chevron angles (X,X1). The 1st pavilion short half angles (Y) along the cable of alternate pairs of chevron facets have a variance of 0.05 to 9; (FIG. 5,5a, 11, 11a). The 1.sup.st common interphase of the pavilion short half facets intersects (R) the cable; 2.sup.nd pavilion short lower half angles (Z) around the gemstone at the girdle depth of the 2.sup.nd point, are 0.25 to 8 less than 1.sup.st pavilion short half angles (Y); The angular variance along 2.sup.nd common interphase between pavilion main facets (O) and the adjacent pavilion short half facets (T), is 0.05 to 9, and at the short side interphase of adjacent pavilion main

Claims

1. A symmetrically cut gemstone visually encompassing a heart shape within, comprising an upper table facet, a girdle with girdle main facets separating and distinguishing the table facet from a lower pavilion having a culet and a plurality of pavilion facets emerging upwardly from the culet and arranged around the pavilion surface on either side of an axis line traversing the pavilion along a horizontal plane, and symmetrical to the corresponding pavilion facets across the axis, comprised in the ratio of x: 4x:2x where x is 4, triangoid facets below the girdle, chevron facets and four sided pavilion main facets, all with one vertice pointing towards the culet the pavilion further including: i. the pavilion main facet being kite shaped, with short sides converging at the culet, long sides at first points at a girdle depth of 70 to 86% and the long and short sides at second points at a girdle depth of 88% to 95%; ii. pairs of pavilion short half facets with a first common interphase, faceted out of the culet end side of chevron facets at first pavilion short half angles at the girdle depth of first point, along a cable joining the first points; iii. the first common interphase of the pavilion short half facets intersecting the cable; iv. second pavilion short lower half angles around the girdle depth of the second point, v. the pavilion main facets alternating pavilion short half facets, along a second common interphase being the long sides at an angular variance of 0.05 to 9, and the angle of variance along the short side interphase of adjacent pavilion main facets being 0.05 to 9; and the girdle depth of the first point of one pair of symmetrical pavilion main facets and a point at which the axis line passing through one pair of pavilion short half facets having a common side along the axis line, intersects the cable, being approximately the same, and 0.5% to 10% less than the girdle depths of the remainder pavilion main facets.

2. The gemstone as claimed in claim 1 facets with the triangoid facets having a triangle main angle in the range of 55 to 65, chevron facets with chevron angle in the range of 35 to 45 and first pavilion short half angles being 15 to 30 less than the triangle main angle, and 2 to 9 less than the chevron angles, second pavilion angles being 0.25 to 8 less than first pavilion short half angles and the first pavilion short half angles corresponding to alternate pairs of chevron facets having a variance of 0.05 to 9.

3. The gemstone as claimed in claim 1 wherein the table facet comprises of a central table, surrounded by a plurality of crown-1 facets, an equal number of crown-2 facets, crown corner facets and star corner facets, and double the number of star angle facets and crown upper angle facets.

4. The gemstone as claimed in claim 3, wherein the table facet comprises of four crown 1 facets, four crown-2 facets, four crown corner facets, four star corner facets, eight star angle facets and eight upper angle facets.

5. The gemstone as claimed in claim 3, wherein the triangoid facets are substantially triangular and the chevron facets are comprised of equal number of pairs of substantially triangular and symmetrical pavilion lower half facets, and pavilion lower half corner facets, with the chevron angles of pavilion lower half corner facets being 0.05 to 2.00 greater than the chevron angle of pavilion lower half facet and the first pavilion short half angles corresponding to pairs of pavilion lower half facets being less than that of pavilion lower half corner facets by 0.05 to 5.0.

6. The gemstone as claimed in claim 5, having four to twelve pavilion main facets and four to twelve pavilion lower half facets and four to twelve pavilion lower half corner facets and eight to twenty-four pavilion short half facets and the girdle depth at the first point ranging from 80-86%, and the girdle depth at the second point ranging from 88.5 to 91%.

7. The gemstone as claimed in claim 6, wherein the first pavilion short half angle of each of the pairs of pavilion short half facets is at a variance of 0.20 to 2.0 with the first pavilion short half angle of the adjacent pair of pavilion short half facets and the variation in the corresponding second pavilion short lower half angles is in the range of 0.05 to 4.0.

8. The gemstone as claimed in claim 6, wherein the first pavilion short half angle of each of the pairs of pavilion short half facets is at a variance of 0.20 to 2.0 with the first pavilion short half angle of the adjacent pair of pavilion short half facets and the second pavilion short lower half angle is fixed.

9. The gemstone as claimed in claim 7, having eight pavilion main facets and eight pavilion lower half facets and eight pavilion lower half corner facets and sixteen pavilion short half facets with girdle depth at 1.sup.st point ranging from 80-86%, and girdle depth of second point ranging from 88.5 to 91%, the second pavilion short half lower angle being at least 0.4 to 2 less than the corresponding first pavilion short half angle and the angular variance along the second common interphase ranging from 0.20 to 6.0 and the angular variance along the short side interphase of adjacent pavilion main facets ranging from 0.05 to 4.5.

10. The gemstone as claimed in claim 9 with a pair of symmetrical short half facets also having one common side along the axis line, having a second common vertex at a common point on the cable and axis line, at a girdle depth equivalent to the girdle depth of the longest pavilion main facet with a variance of not more than 15%.

11. The gemstone as claimed in claim 10 with a second pair of symmetrical small pavilion short half facets, having one common side along the axis line, having sides opposite the vertex meet at a girdle depth approximately midway between the first point and the second point of the pavilion main facets nesting the small pavilion short half facets.

12. The gemstone as claimed in claim 11, wherein the girdle depth of the first point of the pavilion main facet with the longest arms represented by R.sub.1 is 80% of the girdle depth and the subsequent first points of the pavilion main facets as represented by R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, and R.sub.8 are at a depth of 1.05 R.sub.1, 1.04 R.sub.1, 1.04 R.sub.1, 1.05 R.sub.1, R.sub.1, 1.07 R.sub.1 and 1.07 R.sub.1 and the girdle depth at which the common interphase between pairs of short half facets intersect the cable as represented by R.sub.1, R.sub.2, V.sub.1, R.sub.4, R.sub.5, R.sub.6, and R.sub.8 are at 1.03 R.sub.1, 1.05 R.sub.1, R.sub.1, 1.04 R.sub.1, 1.03 R.sub.1, 1.01 R.sub.1, and 1.01 R.sub.1.

13. The gemstone as claimed in claim 10, wherein the girdle depth of the first point of the pavilion main facet with the longest arms represented by R.sub.1 is 80% of the girdle depth and the subsequent first points of the pavilion main facets as represented by R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, and R.sub.8 are at a depth of 1.05 R.sub.1, 1.04 R.sub.1, 1.04 R.sub.1, 1.05 R.sub.1, R.sub.1, 1.07 R.sub.1 and 1.07 R.sub.1 and the girdle depth at which the common interphase between pairs of short half facets intersect the cable as represented by R.sub.1, R.sub.2, V.sub.1, R.sub.4, R.sub.5, R.sub.6, and R.sub.8 are at 1.03 R.sub.1, 1.05 R.sub.1, 1.03 R.sub.1, 1.04 R.sub.1, 1.03 R.sub.1, 1.01 R.sub.1, 1.07 R.sub.1 and 1.01 R.sub.1.

14. The gemstone as claimed in claim 1, wherein the table facet comprises of a central table, surrounded by a plurality of crown-1 facets, and an equal number of crown-2 facets, crown corner facets and star corner facets, and double the number of star angle facets, crown upper angle facets and upper corner facets;

15. The gemstone as claimed in claim 14, wherein the table facet comprises of a central table, four crown-1 facets, four crown-2 facets, four crown corner facets, four star corner facets, eight star angle facets, eight upper angle facets and eight upper corner facets.

16. The gemstone as claimed in claim 14, wherein the visually triangular triangoid facets are bounded on either sides of the vertex by two pairs of straight sides in an angular relation ranging from 175 to 179.95, with an arcuate side facing the vertex pointing to the culet, and the chevron facets are comprised of equal number of substantially triangular pavilion lower half facets and polygoid pavilion lower half corner facets, having three straight sides and an arcuate side opposite to the vertex pointing towards the culet, with chevron angles corresponding to the pavilion lower half corner facet being 0.05 to 2.00 greater than the chevron angle alongside of pavilion lower half facet and the first pavilion short half angles corresponding to the pavilion lower half facets being less than that of the pavilion lower half corner facets by 0.05 to 6.0, and the angles along common interphase of each of the lower half facets and the lower half corner facet being in variance with its adjacent facet in the range of 0 to 0.1.

17. The gemstone as claimed in claim 16, wherein the gemstone has four to twelve elongated kite shaped pavilion main facets and four to twelve pavilion lower half facets and four to twelve pavilion lower half corner facets and eight to twenty-four pavilion short half facets and the girdle depth at the first point ranges from 80-86%, and the girdle depth at the second point ranges from 88.5 to 91%.

18. The gemstone as claimed in claim 17 wherein the first pavilion short half angle along the cable corresponding to each of the pavilion short half facets is at a variance of 0.20 to 2.0 with the first pavilion short half angle corresponding to the adjacent pavilion short half facets, and the variation in the corresponding second pavilion short lower half angles being in the range of 0.05 to 4.0.

19. The gemstone as claimed in claim 18, wherein the first pavilion short half angle along the cable corresponding to each of the pairs of pavilion short half facets is at a variance of 0.20 to 2.0 with the first pavilion short half angle along the cable corresponding to the adjacent pair of pavilion short half facets and the second pavilion short lower half angle is fixed.

20. The gemstone as claimed in claim 18, having eight pavilion main facets and eight pavilion lower half facets and eight pavilion lower half corner facets and sixteen pavilion short half facets of which the pairs of pavilion short half facets with a common side along the axis line alone are symmetrical, with girdle depth of first point (R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8) ranging from 80-86%, and second point girdle depth ranging from 88.5 to 91%, the second pavilion short lower half angle being at least 0.4 to 2 less than the corresponding first pavilion short half angle, each facet of the pavilion mains and the adjacent pavilion short half facets, along the second common interphase being at an angular variance of 0.20 to 6.0 and along the short side interphase of adjacent pavilion main facets being in the range of 0.05 to 4.5.

21. The gemstone as claimed in claim 20 with a pair of symmetrical short half facets also having one common side along the axis line, having a second common vertex at a common point on the cable and axis line, at a girdle depth equivalent to the girdle depth of the longest pavilion main facet with a variance of not more than 15%.

22. The gemstone as claimed in claim 21 with a second pair of symmetrical small pavilion short half facets, having one common side along the axis line, having sides opposite the vertex meet at a girdle depth approximately midway between the first point and the second point of the pavilion main facets nesting the small pavilion short half facets.

23. The gemstone as claimed in claim 22, wherein the girdle depth of the first point of the pavilion main facet with the longest arms represented by R.sub.1 is 80% of the girdle depth and the subsequent first points of the pavilion main facets as represented by R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, and R.sub.8 are at a depth of 1.05 R.sub.1, 1.04 R.sub.1, 1.04 R.sub.1, 1.05 R.sub.1, R.sub.1, 1.07 R.sub.1 and 1.07 R.sub.1 and the girdle depth at which the common interphase between pairs of short half facets intersect the cable (RR) as represented by R.sub.1, R.sub.2, V.sub.1, R.sub.4, R.sub.5, R.sub.6, and R.sub.8 are at 1.03 R.sub.1, 1.05 R.sub.1, 1.03 R.sub.1, 1.04 R.sub.1, 1.03 R.sub.1, 1.01 R.sub.1, and 1.01 R.sub.1.

24. The gemstone as claimed in claim 21, wherein the girdle depth of the first point of the pavilion main facet with the longest arms represented by R.sub.1 is 80% of the girdle depth and the subsequent first points of the pavilion main facets as represented by R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, and R.sub.8 are at a depth of 1.05 R.sub.1, 1.04 R.sub.1, 1.04 R.sub.1, 1.05 R.sub.1, R.sub.1, 1.07 R.sub.1 and 1.07 R.sub.1 and the girdle depth at which the common interphase between pairs of short half facets intersect the cable as represented by R.sub.1, R.sub.2, V.sub.1, R.sub.4, R.sub.5, R.sub.6, R.sub.7 and R.sub.8 are at 1.03 R.sub.1, 1.05 R.sub.1, 1.03 R.sub.1, 1.04 R.sub.1, 1.03 R.sub.1, 1.01 R.sub.1, 1.07 R.sub.1 and 1.01 R.sub.1.

25. The gemstone as claimed in claim 12 wherein the outline of the heart along a horizontal plane as seen from the table facet is along the cable joining the first points in the gemstone.

26. The gemstone as claimed in claim 25 wherein the gemstone is a diamond.

27. A method of cutting a symmetrically shaped gemstone to visually encompass a heart shape within, from a gemstone of princess cut or cushion cut having an upper table facet, a girdle separating and distinguishing the table facet from a lower pavilion having a culet, by cutting and chiselling the pavilion surface to have a plurality of pavilion facets comprising of triangoid facets, chevron facets comprising of pavilion lower half facets and pavilion lower half corner facets, pavilion main facets being four sided and kite shaped emerging upwardly from the culet, the pavilion facets in the ratio of x: 4x:2x, where x is 4, cut and polished in the aforesaid order, having one vertex pointing towards the culet, and arranged on either side of an axis line traversing the pavilion along a horizontal plane, each pavilion facet being symmetrical with another across the axis line, each pavilion main facet having short sides cut to converge at the culet, long sides at first points at a girdle depth of 70 to 86%, and the long sides and short sides at second points at a girdle depth of 88% to 96%, such that the facet depth at the first point of one pair of symmetrical pavilion main facets, not having a common side on the axis line, is less than the remainder first points by 0.5% to 10%; cutting and chiselling the pavilion main facet at second pavilion short lower half angles around a girdle depth of the second point with angle of variance at the short side interphase of adjacent pavilion main facets in the range of 0.05 to 9; optionally cutting and chiselling a pair of small pavilion short half facet from the culet end side of a pair of pavilion lower half facets having a common side along the axis line, at first pavilion short half angles, at a girdle depth midway between the first point and second point of the pavilion main facets nesting the pair of small pavilion lower half facets; further cutting and chiselling a second pair of pavilion lower half facets also having a common side along the axis, at first pavilion angles at the girdle depth of the pavilion main facet having the least girdle depth, from a point where the axis line emerges to the pavilion surface to the point of the pavilion main facets nesting such lower half facets to form a pair of pavilion short half facets; further cutting and polishing the culet end side of remaining chevron facets at first pavilion short half angles along a cable connecting all first points at the girdle depth of 70 to 86%, to form remaining pairs of pavilion short half facets with first common interphase intersecting the cable, such that pairs of pavilion short half facets are nested between the long sides of the pavilion main facets.

28. A method as claimed in claim 27, wherein the first pavilion short half angles are 15 to 30 less than the triangle main angle, and 2 to 9 less than the chevron angles, and the second pavilion short lower half angles are 0.25 to 8 less than first pavilion short half angles.

29. The method as claimed in claim 28 wherein the gemstone is of princess cut wherein the table facet is cut, chiselled and polished to have a central table, four crown-1 facets, four crown-2 facets, four crown corner facets and star corner facets, and eight star angle facet and crown upper angle facets.

30. The method as claimed in claim 29, wherein the chevron facets comprising of substantially triangular pavilion lower half facets and pavilion lower half corner facets are cut, chiselled and polished to have chevron angle alongside the pavilion lower facet to be 0.05 to 2.00 less than the chevron angle alongside the pavilion lower half corner facet.

31. The method as claimed in claim 30 wherein the first pavilion short half angles along the cable of alternate pairs of pavilion short half facets are cut and chiselled to be uniform, and to have a variance of 0.05 to 8 with the adjacent pairs and the pavilion main facets and the adjacent pavilion short half facets are further cut, and polished along a second common interphase at angles varying from 0.05 to 9.

32. The method as claimed in claim 31 wherein the gemstone is cut, chiselled and polished to have eight pavilion lower half facets, eight pavilion lower half corner facets, eight pavilion main facets, with pavilion main facets identified as O.sub.3 and O.sub.6 having the least girdle depth, and sixteen pavilion short half facets and first pavilion short half angles with girdle depth ranging from 80-86%, being 2 to 6 less than the chevron angles and further cutting and polishing such that first pavilion short half angle of each of the pairs of pavilion short half facets is at a variance of 0.20 to 2.0 with the first pavilion short half angle of the adjacent pair of pavilion short half facets, and the second pavilion short lower half angles at the second point with girdle depth ranging from 88.5 to 91%, is at least 0.4 to 2 less than the first pavilion short half angle and further cutting and polishing each facet of the pavilion mains and the adjacent pavilion short half facets such that the angle along the second common interphase varies in the range of 0.20 to 6.0 and the angle along the third common interphase varies in the range of 0.05 to 4.5.

33. The method as claimed in claim 32, wherein the second pavilion short lower half angles are constant around the pavilion main facets.

34. The method as claimed in claim 32, wherein the girdle depth of the first point of the pavilion main facet with the longest arms represented by R.sub.1 is 80% of the girdle depth and the subsequent first points of the pavilion main facets as represented by R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, and R.sub.8 are at a depth of 1.05 R.sub.1, 1.04 R.sub.1, 1.04 R.sub.1, 1.05 R.sub.1, R.sub.1, 1.07 R.sub.1 and 1.07 R.sub.1 and the girdle depth at which the common interphase between pairs of short half facets intersect the cable as represented by R.sub.1, R.sub.2, V.sub.1, R.sub.4, R.sub.5, R.sub.6, and R.sub.8 are at 1.03 R.sub.1, 1.05 R.sub.1, R.sub.1, 1.04 R.sub.1, 1.03 R.sub.1, 1.01 R.sub.1, and 1.01 R.sub.1.

35. The method as claimed in claim 32, wherein the girdle depth of the point of the pavilion main facet with the longest arms represented by R.sub.1 is 80% of the girdle depth and the subsequent points of the pavilion main facets as represented by R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, and R.sub.8 are at a depth of 1.05 R.sub.1, 1.04 R.sub.1, 1.04 R.sub.1, 1.05 R.sub.1, R.sub.1, 1.07 R.sub.1 and 1.07 R.sub.1 and the girdle depth at which the common interphase between pairs of short half facets intersect the cable as represented by R.sub.1, R.sub.2, V.sub.1, R.sub.4, R.sub.5, R.sub.6, R.sub.7 and R.sub.8 are at 1.03 R.sub.1, 1.05 R.sub.1, R.sub.1, 1.04 R.sub.1, 1.03 R.sub.1, 1.01 R.sub.1, 1.07 R.sub.1 and 1.01 R.sub.1.

36. The method as claimed in claim 27, wherein the gemstone is of cushion cut and the table facet is cut to comprise of one central table (A), four crown-1 facets, four crown-2 facets, crown corner facets, four star corner facets, eight star angle facets, eight upper angle facets and eight upper corner facets.

37. The method as claimed in claim 27, wherein the chevron facets comprising of substantially triangular pavilion lower half facets and polygoid pavilion lower half corner facets with an arcuate side opposite the vertex pointing to the culet, are cut, chiselled and polished to have chevron angle alongside the pavilion lower facet to be 0.05 to 2.00 less than the chevron angle alongside the pavilion lower half corner facet.

38. The method as claimed in claim 37 wherein the first pavilion short half angles of pavilion short half facets other than those with a common side along the axis line, are cut and chiselled to have a variance of 0.05 to 9 with its adjacent pair, and the second common interphase of each facet of the pavilion main facet and the adjacent pavilion short half facets are further cut, chiselled and polished to have an angular variance in the range of 0.05 to 9.

39. The method as claimed in claim 38 wherein the gemstone is cut, chiselled and polished to have eight pavilion lower half facets and eight pavilion lower half corner facets, eight pavilion main facets with pavilion main facets identified as O3 and O6 having the least girdle depth, and sixteen pavilion short half facets and the first pavilion short half angles with girdle depth ranging from 80-86%, being 2 to 6 less than the chevron angles and further cutting and polishing such that first pavilion short half angle of each of the pairs of pavilion short half facets is at a variance of 0.20 to 2.0 with the first pavilion short half angle of the adjacent pair of pavilion short half facets, and the second pavilion short lower half angles at the second point with girdle depth ranging from 88.5 to 91%, is at least 0.4 to 2 less than the first pavilion short half angle and further cutting and polishing each facet of the pavilion mains and the adjacent pavilion short half facets such that the angle along the second common interphase varies in the range of 0.20 to 6.0 and the angle along the common interphase varies in the range of 0.05 to 4.5.

40. The method as claimed in claim 39, wherein the second pavilion short lower half angles are constant around the pavilion main facets.

41. The method as claimed in claim 39, wherein the girdle depth of the first point of the pavilion main facet with the longest arms represented by R1 is 80% of the girdle depth and the subsequent first points of the pavilion main facets as represented by R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, and R.sub.8 are at a depth of 1.05 R1, 1.04 R1, 1.04 R1, 1.05 R1, R1, 1.07 R1 and 1.07 R1 and the girdle depth at which the common interphase between pairs of short half facets intersect the cable as represented by R.sub.1, R.sub.2, V.sub.1, R.sub.4, R.sub.5, R.sub.6 and R.sub.8 are at 1.03 R1, 1.05 R1, 1.03 R1, 1.04 R1, 1.03 R1, 1.01 R1 and 1.01 R1.

42. The method as claimed in claim 39, wherein the girdle depth of the first point of the pavilion main facet with the longest arms represented by R1 is 80% of the girdle depth and the subsequent first points of the pavilion main facets as represented by R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, and R.sub.8 are at a depth of 1.05 R.sub.1, 1.04 R.sub.1, 1.04 R.sub.1, 1.05 R.sub.1, R.sub.1, 1.07 R.sub.1 and 1.07 R.sub.1 and the girdle depth at which the common interphase between pairs of short half facets intersect the cable as represented by R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7 and R.sub.8 are at 1.03 R.sub.1, 1.05 R.sub.1, 1.03 R.sub.1, 1.04 R.sub.1, 1.03 R.sub.1, 1.01 R.sub.1, 1.07 R.sub.1 and 1.01 R.sub.1.

43. The method as claimed in claim 34 wherein the gemstone is a diamond.

44. The method as claimed in claim 34 wherein the cable joining the first points in the gemstone, form an outline of a heart shape along a horizontal plane as viewed from the table facet.

Description

DRAWINGS

[0019] FIG. 1: The princess cut gemstone side view.

[0020] FIG. 2 Table view of double crown princess cut gemstone

[0021] FIG. 2 a: Crown top side angles of double crown princess cut gemstone.

[0022] FIG. 3: Pavilion view of princess cut gemstone

[0023] FIG. 4: Exploded view of pavilion Main facets showing cable

[0024] FIG. 4 (a) Exploded view of pavilion Main facets

[0025] FIG. 4(b) Exploded view of pavilion main facets

[0026] FIG. 5: Pavilion angles in side view of a princess cut gemstone along pavilion lower half corner facet.

[0027] FIG. 5a: Pavilion angles in side view of a princess cut gemstone along pavilion lower half facet.

[0028] FIG. 6: angles in pavilion view of a princess cut gemstone

[0029] FIG. 6a: girdle depth of 1st and 2nd Point on Pavilion of princess cut gemstone

[0030] FIG. 7: table view of princesscut gemstone, showing heart shape in the centre.

[0031] FIG. 8: The cushion cut gemstone side view.

[0032] FIG. 9: Table view of double crown cushion cut gemstone

[0033] FIG. 9 (a): Table side angle view of double crown cushion cut gemstone

[0034] FIG. 10: Pavilion view of cushion cut gemstone

[0035] FIG. 11: Pavilion angles in side view of a cushion cut gemstone along pavilion lower half facet

[0036] FIG. 11(a) Pavilion angles in side view of a cushion cut gemstone along pavilion lower half corner facet

[0037] FIG. 12: angle variations of adjacent facets in cushion shaped diamond.

[0038] FIG. 13: girdle depth of 1st and 2nd Point on Pavilion.

[0039] FIG. 14: table view of cushion shaped gemstone, showing heart shape in the centre.

DESCRIPTION

[0040] In its main embodiment the invention describes a symmetrically cut gemstone, preferably of princess cut or cushion cut, which visually encompasses a heart shape within. (FIG. 7, 14) The gemstone of the present description, as commonly available in commerce, as seen in its side view (FIG. 1, 8) is basically divided in to 3 regions: i. The upper face of the gemstone which is referred to as the upper crown table facet (A). ii. The region below the table facet is referred to as the girdle (B). iii. The lower part of the gemstone, i.e the region below the girdle is referred to as the pavilion (C); The girdle separates and distinguishes the table facet from the pavilion. The lower most pointed tip of the pavilion is referred to as the culet (D)

[0041] The princess cut and cushion cut gemstone as described in this invention can have a upper crown table facet comprising of a single crown or double crown.

[0042] In case of a princess cut gemstone with a double crown table facet, as seen in FIG. 2, the table facet is comprised of a central table (A), surrounded by a plurality of crown-1 facets (E), and an equal number of crown-2 facets, (F), crown corner facets (G) and star corner facets (H) and double the number of star angle facets (.I) and crown upper angle facets (J). In a preferred embodiment of the invention, as seen at FIG. 2 in case of double crown princess cut gemstones, the table facet is comprised of a central table (A), surrounded by 4 crown-1 facets (E.sub.1 to E.sub.4), 4 crown-2 facets (F.sub.1 to F.sub.4), 4 crown corner facets (G.sub.1 to G.sub.4), 4 star corner facets (H.sub.1 to H.sub.4), 8 star angle facets (I.sub.1 to I.sub.8), and 8 upper angle facets (J.sub.1 to J.sub.8)

[0043] In case of a cushion cut gemstone, with a double crown, as seen in FIG. 9, the table facet comprises of a central table (A), plurality of crown-1 facets (E), an equal number of crown-2 facets (F), half the number of crown corner facets (G) and star corner facets (H), and equal number of star angle facets (I), crown upper angle facets (J) and upper corner facets (K); In a preferred embodiment of the invention as seen at FIG. 9 in case of double crown cushion cut gemstones, the table facet is comprised of a central table (A), 4 crown-1 facets (E.sub.1 to E.sub.4), 4 crown-2 facets (F.sub.1 to F.sub.4), 4 crown corner facets (G.sub.1 to G.sub.4), 4 star corner facets (H.sub.1 to H.sub.4), 8 star angle facets (I.sub.1 to I.sub.8), 8 upper angle facets (J.sub.1 to J.sub.8) and 8 upper angle corner facets (K.sub.1 to K.sub.8).

[0044] The crown angles on the Upper double crown table are at recommended angles as seen in FIGS. 2(a) and 9(a). The crown facet angles are usually in the range as seen in Table 1 below:

TABLE-US-00001 TABLE 1 Name Number Ideal angle Ideal angle of of Angle For princess For cushion facet facets range cut cut E1 to E4 4 25-65 38.00 36 F1 to F4 4 20-55 32.00 29 G1 to G4 4 15-45 24.36 33 H1 to H4 4 14-45 19.90 23 I1 to I8 8 15-45 19.70 22 J1 to J8 8 25-65 39.96 39 K1 TO K8 8 40

[0045] No claim is being made exclusively in respect of the crown angles or the crown table, but only in its novel combination with the pavilion as described in this invention.

[0046] As seen in FIGS. 3 and 10. the pavilion which has a plurality of pavilion facets on the pavilion surface, comprise of the following: (i) Triangoid facets (L), (ii). Chevron facets (M,N) comprising of equal number of pavilion lower half corner facets (N) and) substantially triangular pavilion lower half facets (M), (iii) pavilion Main facets (O) and iv. Pairs of pavilion short half facets (T). All the facets have at least one vertice pointing towards the culet. (D) The pavilion facets are cut and chiselled to emerge upwardly from the culet (D) and are arranged on either side of an axis line (C.sub.1) that traverses the pavilion along the horizontal plane. Each of the pavilion facets has a symmetrical pair across the axis line.

[0047] In the gemstone of the present invention, the triangle main angle (W), i.e the angle formed by the girdle and the triangoid facets, is in the range of 55 to 65, and the chevron angle i.e the angle formed by the triangle main facet with the chevron facets is in the range of 35 to 45 as seen in FIG. 5. 5(a), 11,11(a). The triangle main angle value and chevron angle value could vary over the above mentioned range, and the invention would not be affected.

[0048] The Triangoid facets (L), the chevron facets (M, N) and the pavilion main facets (O) are in the ratio of x: 4x:2x, where X is 4 and an even number. The chevron facets comprise of pavilion lower half corner facets (N) and substantially triangular pavilion lower half facets (M). The adjacent pairs of pavilion lower half corner facets (N) are symmetrical. The pairs of pavilion lower half facets alternate pairs of pavilion lower half corner facets.

[0049] In a princess cut gemstone, (FIG. 3) the triangoid facets (L) are substantially triangular and the chevron facets are comprised of equal number of pairs of substantially triangular and symmetrical, pavilion lower half facets (M) and pavilion lower half corner facets (N), with the chevron angles of pavilion lower half corner facets (X1) being 0.05 to 2.00 greater than the chevron angle of pavilion lower half facet (X).

[0050] In a cushion cut gemstone, (FIG. 8, 10) the visually triangular triangoid facets are bounded on either sides of the vertex (pointing to the culet) by two pairs of straight sides in an angular relation ranging from 175 to 179.95, with an arcuate side facing that vertex. The chevron facets are comprised of equal number of substantially triangular pavilion lower half facets (M) and polygoid pavilion lower half corner facets (N), having 3 straight sides and an arcuate side opposite to the vertex pointing towards the culet. The chevron angles (X1) of pavilion lower half corner facet is 0.05 to 2.00 greater than the chevron angle of pavilion lower half facet (X).

[0051] As seen in FIGS. 3, 4, 4(a), 4(b), and 10, the pavilion main facets (O) of a princess cut and cushion cut gemstone are similar in the number of pavilion lower half facets (M) and pavilion lower half corner facets (N). The pavilion main facet (O) are four sided and preferably kite shaped, emerging upwardly from the culet, with short sides (P) converging at the culet, long sides (Q) at 1.sup.st points (R) at a girdle depth of 70 to 86% and the long and short sides at 2.sup.nd points (S) at a girdle depth of 88% to 95%. The girdle depth of the 1.sup.st point of one pair of symmetrical pavilion main facets and is 0.5% to 10% less than the girdle depth of the 1.sup.st point of the remainder pavilion main facets. (FIG. 4,6(a), 13.), thus making this pair the longest pavilion main facet. The girdle depth of the girdle is considered as 0% and that of the culet as 100%.

[0052] Pairs of pavilion short half facets are nested between the long sides of the pavilion main facets (O). The pavilion short half facets (T), are faceted out of the culet end side of chevron facets (M,N), at 1.sup.st pavilion angles around the depth of the 1.sup.st point along a cable (RR) joining the 1.sup.st points (R). The angle formed by the pavilion short half facets and the remaining chevron facet is referred to as the 1.sup.st pavilion short half angle. (Y). The 1.sup.st pavilion angles are formed around the pavilion at a girdle depth of the 1.sup.st point forming the cable (RR). The pairs of pavilion short half facets have a common side, referred to as the 1.sup.st common interphase, which is continuous with the common side of the corresponding pairs of chevron facets. The 1.sup.st common interphase, separating the adjacent pairs of pavilion short half facets intersects the cable (RR) at R. Two pairs of pavilion short half facets have a common side along the axis line.

[0053] One of the pairs of symmetrical short half facets having one common side along the axis line, has a second common vertex (V) at a common point on the cable (RR) and axis line at a girdle depth approximately equivalent to the girdle depth of the longest pavilion main facet (O). In order to obtain the shape of a heart, it is recommended that the variance in girdle depth of V be within 15% of the recommended girdle depth. (FIG. 4, 4a,).

[0054] The 1.sup.st pavilion short half angle is 15 to 30 less than the Triangle main angle (W), and 2 to 9 less than the chevron angles (X,X1). The 1.sup.st pavilion short half angles (Y) corresponding to alternate pairs of chevron facets vary from 0.05 to 9 in the outer limit; (FIG. 6, 12). The pavilion main facets at the girdle depth of the 2.sup.nd point are cut and chiselled at 2.sup.nd pavilion short lower half angles (Z) which are 0.25 to 8 less than 1.sup.st pavilion short half angles (Y). Thus the girdle depth of the final gemstone after chiselling the 2.sup.nd pavilion short lower half angles, is less than the original gemstone The pavilion mains (O) facets and the adjacent pavilion short half facets (T), along their common interphase (referred to as the 2.sup.nd common interphase) are at an angle which angle value varies amongst the 2.sup.nd common interphases by 0.05 to 9. The shortside interphase (Q) of adjacent pavilion main facets are also at an angle and the angle value varies in the range of 0.05 to 9.

[0055] In a princess cut gemstone, the 1.sup.st pavilion short half angles (Y) corresponding to pairs of pavilion lower half facets is less than that of pavilion lower half corner facets by 0.05 to 5.0.

[0056] In a cushion cut gemstone, the 1.sup.st pavilion short half angles (Y) corresponding to pavilion lower half facets are less than that of the pavilion lower half corner facets by 0.05 to 5.0. Further the 1.sup.st pavilion short half angle (Y) of each of the lower half facets and the lower half corner facet are in variance with its corresponding adjacent facet in the range of 0 to 0.1

[0057] In a workable embodiment, the pavilion of the gemstone comprises of 4 to 12 pavilion main facets (O) and 4 to 12 pavilion lower half facets (M) and 4 to 12 pavilion lower half corner facets (.N) and 8 to 24 pavilion short half facets (T) and the girdle depth at the 1.sup.st point ranges from 80-84.5%, and the facet depth at the 2.sup.nd point ranges from 88.5 to 91%.

[0058] In an improved embodiment of this invention, in respect of the princess cut and cushion cut gemstone, the 1.sup.st pavilion short half angle (Y) of each of the pairs of pavilion short half facets (T) is at a variance of 0.20 to 2.0 with the 1.sup.st pavilion short half angle (T) of the adjacent pair of pavilion short half facets and the variation in the corresponding 2.sup.nd pavilion short lower half angles (Z) is in the range of 0.05 to 4.0. In another embodiment of this invention, the 2.sup.nd pavilion short lower half angles. (Z) remain the same in all pavilion main facets.

[0059] In a precise embodiment of this invention as described above, the gemstone of princess cut has 8 pavilion main facets (O.sub.1 to O.sub.8) and 8 pavilion lower half facets (M.sub.1 to M.sub.8) and 8 pavilion lower half corner facets (N.sub.1 to N.sub.8)) and 16 pavilion short half facets (T.sub.1 to T.sub.16). The pairs of pavilion short half facets with a common side along the axis line are T.sub.1, T.sub.16, and T.sub.8, T.sub.9. The small pavilion short half facets are T.sub.1, T.sub.16, and are nested between pavilion main facets O.sub.4 and O.sub.5. (FIG. 3, 4, 4a) The longest pavilion main facets are O.sub.3 and O.sub.6, with 1.sup.st points at about 81% of the girdle depth. The girdle depth of the 1.sup.st point (R) ranges from 80-86%, and that of the 2.sup.nd point (S) ranges from 88.5 to 91%. (FIG. 6(a)) Each facet of the pavilion mains (O) and the adjacent pavilion short half facets (T), along its common interphase are at an angular variance ranging from 0.20 to 6.0 and the angular variance along the short side interphase of adjacent pavilion main facets (O) ranges from 0.05 to 4.5. The 2.sup.nd pavilion short lower half angle (Z) of the gemstone of this invention is at least 0.4 to 2 less than the corresponding 1.sup.st pavilion short half angle (Y). (FIG. 6)

[0060] In a precise embodiment of this invention as described above, the gemstone of cushion cut has 8 pavilion main facets (O1 to O8) and 8 pavilion lower half facets (M1 to M8) and 8 pavilion lower half corner facets (N1 to N8)) and 16 pavilion short half facets (T.sub.1 to T.sub.16). The pairs of pavilion short half facets with a common side along the axis line are T.sub.1, T.sub.16, and T.sub.8, T.sub.9. The small pavilion short half facets are T.sub.1, T.sub.16, and are nested between pavilion main facets O.sub.4 and O.sub.5. (FIG. 10, 4, 4a) The longest pavilion main facets are O.sub.3 and O.sub.6, with 1.sup.st points at about 81% of the girdle depth. The pairs of pavilion short half facets with a common side along the axis line alone are symmetrical. The ideal girdle depth of 1.sup.st point (R) ranges from 80-86%, and that of the 2.sup.nd point (S) ranges from 88.5 to 91%. Each facet of the pavilion mains (O) and the adjacent pavilion short half facets (T) along the common interphase are at an angular variance of 0.20 to 6.0 in relation to each other and the angle of variance between culet side ends of adjacent pavilion main facets (O) along its common interphase ranges from 0.05 to 4.5. The 2.sup.nd pavilion short lower half angle (Z) of the gemstone of this invention is at least 0.4 to 2 less than the corresponding 1.sup.st pavilion short half angle (Y).

[0061] The suggested girdle depths in order to obtain a design of the heart within the gemstone, both cushion and princess cut is in relation to the the girdle depth of the 1.sup.st point of the pavilion main facet with the longest arms represented by R.sub.1, which is 80% of the girdle depth of the gemstone. The subsequent 1.sup.st points of the pavilion main facets as represented by R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, and R.sub.8 are at a depth of 1.05 R.sub.1, 1.04 R.sub.1, 1.04 R.sub.1, 1.05 R.sub.1, R.sub.1, 1.07 R.sub.1 and 1.07 R.sub.1. The girdle depth at which the common interphase between pairs of short half facets intersect the cable (RR) as represented by R.sub.1, R.sub.2, V.sub.1, R.sub.4, R.sub.5, R.sub.6, and R.sub.8 are at 1.03 R.sub.1, 1.05 R.sub.1, 1.03 R.sub.1, 1.04 R.sub.1, 1.03 R.sub.1, 1.01 R.sub.1, 1.07 R.sub.1 and 1.01 R.sub.1.

[0062] The sharpness of the shape of the heart within the gemstone is obtained by minimising the angular difference between the 1.sup.st pavilion short half angles and the 2.sup.nd pavilion short lower half angles.

[0063] In a commercially attractive embodiment of this invention in respect of princess cut and cushion cut gemstones, the 2.sup.nd pair of pavilion short half facets having a common side along the axis line, at the azimuth angle of approximately 60 to 220, are smaller than the remaining pavilion short half facets. The sides (U) opposite to the vertex of these small pavilion short half facets, converge at a point (V) along the common axis line, which is midway between the girdle depth of the 1.sup.st point and 2.sup.nd point of the pavilion main facets, nesting these small pavilion short half facets. This creates the indent to give a perfect shape of the heart when the gemstone is seen from the pavilion view or the table view. (FIG. 7, 14)

[0064] The suggested girdle depths in order to create a heart shape design with an indent is in relation to the girdle depth of the 1.sup.st point of the pavilion main facet with the longest arms represented by R.sub.1, which is at 80% of the girdle depth and the subsequent 1.sup.st points of the pavilion main facets as represented by R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, and R.sub.8 are at a depth of 1.05 R.sub.1, 1.04 R.sub.1, 1.04 R.sub.1, 1.05 R.sub.1, R.sub.1, 1.07 R.sub.1 and 1.07 R.sub.1. The the girdle depth at which the common interphase (P) between pairs of short half facets intersect the cable (RR) as represented by R.sub.1, R.sub.2, V.sub.1, R.sub.4, R.sub.5, R.sub.6, and R.sub.8 are at 1.03 R.sub.1, 1.05 R.sub.1, R.sub.1, 1.04 R.sub.1, 1.03 R.sub.1, 1.01 R.sub.1, and 1.01 R.sub.1.

[0065] Table 2 below gives the percentage depth of the pavilion main facets, pavilion lower half facets, pavilion lower half corner facets and pavilion short half facets, the 1.sup.st pavilion short half angle and the 2.sup.nd pavilion short lower half angle with reference to the girdle, where girdle is considered as 0 and culet as 100.

TABLE-US-00002 TABLE 2 Range of Girdle Depth Range of Short Number Ideal for Girdle Names of Girdle princess Depth for Name of facet of Facets facets Depth cut cushion cut Triangle Mains L.sub.1 To L.sub.4 4 60 to 65 25 to 75 25 to 75 Angles (W) Chevron 1 M.sub.1To M.sub.8 8 78 to 82 65 to 85 60 to 82 angle (Pavilion Lower Halves Facets) X Chevron 2 N.sub.1 To N.sub.8 8 78 to 85 65 to 88 60 to 88 angle (Pavilion Lower Halves Corner Facets)X-1 1.sup.ST T.sub.1 To T.sub.16 16 82 to 85 70 to 85 65 to 85 Pavilion (Short) Halves Angle (Facets) (Y) 2.sup.nd Pavilion O.sub.1 To O.sub.8 8 91 to 96 80 to 96 75 to 96 Angle (Z)

[0066] At FIG. 6(a), 13 is seen one such representation showing girdle depth at which desired results of a perfect heart shape is achieved.

[0067] Table 3 below gives the azimuth index range at which the pavilion main facets, pavilion lower half facets, pavilion lower half corner facets and pavilion short half facets, the 1.sup.st pavilion short half angles and the 2.sup.nd pavilion short lower half angles are around the gemstone.

TABLE-US-00003 TABLE 3 Range Range of of Girdle Girdle Depth Depth Short Number Ideal for for Names of of Girdle princess cushion Name of facet Facets facets Depth cut cut Triangle Mains L1 To L4 4 60 to 65 25 to 75 25 to 75 Angles (W) Chevron 1 M1 To M8 8 78 to 82 65 to 85 60 to 82 angle (Pavilion Lower Halves Facets) X Chevron 2 N1 To N8 8 78 to 85 65 to 88 60 to 88 angle (Pavilion Lower Halves Corner Facets)X-1 1.sup.ST T1 To 16 82 to 85 70 to 85 65 to 85 Pavilion (Short) T16 Halves Angle (Facets) (Y) 2.sup.nd Pavilion O1 To O8 8 91 to 96 80 to 96 75 to 96 Angle (Z)

[0068] Table 4 gives the range of angle variation between the chevron facets, the pavilion short half facets and pavilion main facets at which it is possible to obtain a heart shape within the gemstone.

TABLE-US-00004 TABLE 4 IDEAL ANGLE NAME IDEAL for IDEAL OF No. OF FACET ANGLE princess ANGLE for FACET FACETS NO. RANGE cut cushion cut L.sub.1 to L.sub.4 4-12 4 45-75 62.00 58.00 M.sub.1 to M.sub.8 4-12 8 25-65 39.56 40.50 N.sub.1to N.sub.8 4-12 8 25-65 39.80 40.60 T.sub.1to T.sub.16 8-24 16 36.55 37.50 O.sub.1to O.sub.8 4-12 8 25-45 36 37 Difference *** 0.01-8.0 3.0 3.0 in M, N, &T Difference ** * 0.01-8.0 0.5 0.5 T & O

[0069] In another main embodiment for manufacture of the symmetrically cut gemstone, visually encompassing a heart shape (Z1) within, a gemstone of princess cut or cushion cut is obtained by a process known in the art. A symmetrically shaped princess cut or cushion cut gemstone has an upper table facet (A), a girdle (B) which separates and distinguishes the table facet (A) from a lower pavilion (C), which is cone shaped. The tip of the cone is referred to as the culet (D). Cutting and polishing of the table facets and the pavilion facets both contribute to obtaining optimum lustre, radiance and brilliance in a gemstone like a diamond.

[0070] The upper table facet may consist of a single crown or a double crown. In case of a double crown in a princess cut gemstone, the upper table facet of the gemstone is cut chiseled and polished to form a central table facet (A.sub.1), surrounded by a plurality of crown-1 facets (E), and an equal number of crown-2 facets, (F), crown corner facets (G) and star corner facets (H) and double the number of star angle facets (.I) and crown upper angle facets (J). In a preferred embodiment of the invention, as seen at FIG. 2 a double crown princess cut gemstones, the table facet is cut, chiseled and polished to comprised of a central table (A), surrounded by 4 crown-1 facets (E.sub.1 to E.sub.4), 4 crown-2 facets (F.sub.1 to F.sub.4), 4 crown corner facets (G.sub.1 to G.sub.4), 4 star corner facets (H.sub.1 to H.sub.4), 8 star angle facets (I.sub.1 to I.sub.8), and 8 upper angle facets (J.sub.1 to J.sub.8)

[0071] In case of a cushion cut gemstone, with a double crown, as seen in FIG. 9, the upper crown table facet is cut, chiselled and polished to comprise of a central table (A), plurality of crown-1 facets (E), an equal number of crown-2 facets (F), half the number of crown corner facets (G) and star corner facets (H), and equal number of star angle facets (I), crown upper angle facets (J) and upper corner facets (K); In a preferred embodiment of the invention as seen at FIG. 9 in case of double crown cushion cut gemstones, the table facet is cut, chiselled and polished to comprise of a central table (A), 4 crown-1 facets (E.sub.1 to E.sub.4), 4 crown-2 facets (F.sub.1 to F.sub.4), 4 crown corner facets (G.sub.1 to G.sub.4), 4 star corner facets (H.sub.1 to H.sub.4), 8 star angle facets (I.sub.1 to I.sub.8), 8 upper angle facets (J.sub.1 to J.sub.8) and 8 upper angle corner facets (K.sub.1 to K.sub.8).

[0072] The crown angles are determined by viewing the gemstone from a side profile and visually estimating the angle of the top portion of the gemstone. The upper crown-1 angle cut is in the range of 38 to 52, and the respective azimuth angle of the 4 side facets are 0, 90, 180 and 270 respectively. At the same azimuth angle, the Crown-2 facets are at an angle in the range of 25 to 40. Crown 2 facets are optional. Crown 2 facets add more brightness to the stone. The star angle facets and the star corner facets are placed in the corner at 18 to 20 of all four sides. The star corner facets are at azimuth angles of 45, 135, 225 and 315. The crown upper angle facets (J) are preferably placed at angle of about 40 In case of cushion cut gemstones, upper corner facets (K) are placed preferably at an angle of 40.

[0073] The pavilion is cut, chiselled and polished to have a plurality of pavilion facets, comprising of triangoid facets, chevron facets and pavilion main facets at heights, azimuth and facet angles in the manner known in the art, in the ratio of x: 4x:2x, where x is 4. The gemstone is cut and chiseled to form a plurality of triangoid facets (L), downwardly from the girdle, with triangle main angles (W) in the range of 55 to 65. The chevron facets (M,N) comprising of pavilion lower half facets (M) and pavilion lower half corner facets (N), also are cut and polished, such that the chevron angles (X,X1) are in the range of 35 to 45. The pavilion lower half corner facets (N) extend from the girdle to the culet. The pavilion lower half facets (M) extend downwardly from the triangoid facets to the culet. (D). To enable the invention, the chevron facets are cut and chiselled at heights, facet angles, and azimuth, such that 4 sided pavilion main facets (O) emerge upwardly from the culet. The pavilion main facets are preferably kite shaped having a common interphase with culet side ends of the chevron facets. The pavilion main facets are cut to have a pair of shortsides (P) and a pair of longsides (Q); The short sides (P) of the pavilion main facet are cut, chiselled and polished to converge at the culet and the long sides (Q) at 1.sup.st points (R) which are at a girdle depth in the range of 70 to 86%. Each of the pair of long side and short side are cut to converge at 2.sup.nd points (S) at a girdle depth varying from 88% to 96%. The facets are cut and polished in the aforesaid order, and arranged on either side of an axis line (C) traversing the pavilion along a horizontal plane. Each pavilion facet is symmetrical with another across the axis line and all pavilion facets have one vertex pointing towards the culet. For the purpose of this embodiment, one pair of symmetrical pavilion main facets (O.sub.3,O.sub.6) which does not have any side along the axis plane, is cut to have a facet depth at the 1.sup.st point (R) to be less than the remainder 1.sup.st points by 0.5% to 10%, thus making this pair the longest pavilion main facet. The chevron facets (M.N) are cut and chiselled from the culet end side at the girdle depth of 70 to 86%, to form pairs of pavilion short half facets (T). A pair of adjacent symmetrical pavilion lower half facets having one common side along the axis is further cut, chiselled and polished at 1.sup.st pavilion angles at the girdle depth of the 1.sup.st point of pavilion main facets having the shortest girdle depth (O.sub.3, O.sub.6) with a variance of not more than 15%, from the point (V.sub.1) the axis line emerges on the pavilion surface to the 1.sup.st points of the pavilion main facets flanking such pavilion lower half facet. In a table view, the cable (RR) would appear to connect 1.sup.st points R.sub.3 and R.sub.4 at V.sub.1.

[0074] The adjacent pairs of short half facets have a 1.sup.st common interphase (P), which is also the common interphase for the corresponding pair of pavilion lower half facets. The chevron facets are chiselled at 1.sup.st pavilion short half angles (Y) along a cable (RR) connecting the 1.sup.st points, to form the pavilion short half facets such that pairs of pavilion short half facets (T) alternate the long sides (Q) of the pavilion main facets (O). The pavilion short half facets are also symmetrical to the corresponding pavilion short half facet across the axis line. The 1.sup.st common interphase of the pavilion short half facets intersect the cable at (R). The 1.sup.st pavilion short half angles are 15 to 30 less than the triangle main angle, and 2 to 9 less than the chevron angles (X,X1).

[0075] In case of princess cut gemstones, as seen at FIG. 3, the chevron facets comprising of substantially triangular pavilion lower half facets (M) and pavilion lower half corner facets (N) are cut, chiselled and polished to have chevron angle (X) alongside the pavilion lower facet to be 0.05 to 2.00 less than the chevron angle (X1) alongside the pavilion lower half corner facet. Further as seen at FIG. 6, the 1.sup.st pavilion short half angles (Y) along the cable (R) of alternate adjacent pavilion short half facets from corresponding chevron facets are uniform, and having a variance of 0.05 to 8 with the adjacent pairs;

[0076] In case of cushion cut gemstones, as seen at FIG. 10, the chevron facets are formed to comprise of substantially triangular pavilion lower half facets (M) and polygoid pavilion lower half corner facets (N) with an arcuate side opposite the vertex pointing to the culet. These facets are cut, chiselled and polished to have chevron angle (X) alongside the pavilion lower facet to be 0.05 to 2.00 less than the chevron angle (X1) alongside the pavilion lower half corner facet. Further, as seen in FIG. 12, the pairs of pavilion short half facets having a common side along the axis line are chiselled so that 1.sup.st pavilion short half angles (Y) is the same as its adjacent pair. Further the 1.sup.st pavilion short half angles (Y) of the remaining short half facets are cut, chiselled and polished to have a variance of 0.05 to 9 with its adjacent pair. The angle formed along the 2.sup.nd common interphase (Q) of each facet of the pavilion main facet (O) and the adjacent pavilion short half facets (T) are further cut, chiselled and polished to have an angular variance in the range of 0.05 to 9 in its outer limit.

[0077] In both the princess cut and cushion cut gemstones, the angle along the 2.sup.nd common interphase of each facet of the pavilion mains (O) and the adjacent pavilion short half facets (T) are cut to vary in the range of 0.05 to 9.

[0078] The pavilion main facets are further cut polished and chiselled at 2.sup.nd pavilion short lower half angles (Z) which are 0.25 to 8 less than 1.sup.st pavilion short half angles, at the girdle depth of the 2.sup.nd point (S). The angle so formed along the short side interphase (P) of adjacent pavilion main facets varies in the range of 0.05 to 9.

[0079] In a commercial embodiment of the invention, the gemstone as described above is cut, chiselled and polished to have 8 pavilion main facets (O.sub.1 to O.sub.8) and 8 pavilion lower half facets (M.sub.1 to M.sub.8) and 8 pavilion lower half corner facets (N.sub.1 to N.sub.8)) and 16 pavilion short half facets (T.sub.1 to T.sub.16). The pair of pavilion main facets having the shortest girdle depth are identified as O.sub.3 and O.sub.6. The pairs of short half facets having a common side along the axis line are identified as T.sub.1,T1.sub.6 and T.sub.8,T.sub.9. The small pavilion short half facets are identified as T.sub.8 and T.sub.9. The girdle depth of 1.sup.st pavilion short half angles (Y) range from 80-86%, and are ideally 2 to 6 less than the chevron angles (X,X1). The gemstones are further cut and polished such that 1.sup.st pavilion short half angle of each pair of pavilion short half facets is at a variance of 0.20 to 2.0 with the 1.sup.st pavilion short half angle of the adjacent pair of pavilion short half facets. The pavilion main facet is also further cut and chiselled such that the 2.sup.nd pavilion short lower half angles (Z) at the 2.sup.nd point (S) is at a girdle depth ranging from 88.5 to 91%, and at least 0.4 to 2 less than the 1.sup.st pavilion short half angle. The pavilion mains (O) and the adjacent pavilion short half facets (T) are further cut, chiselled and polished such that the angle along the 2.sup.nd common interphase varies in the range of 0.20 to 6.0 and the angle along the 3.sup.rd common interphase varies in the range of 0.05 to 4.5.

[0080] In another embodiment of this invention, 2.sup.nd pavilion short lower half angles are constant around the pavilion main facets (O).

[0081] In order to be able to get the perfect shape of the heart within the gemstone, with the indent the girdle depths of the 1.sup.st points have to be specific and the gemstone is cut and chiselled in specific relation to the girdle depth of the pavilion facet, having the shortest girdle depth. The suggested girdle depth of the 1.sup.st point of the pavilion main facet with the longest arms (O.sub.6) represented by R1 is 80% of the girdle depth and the subsequent 1.sup.st points of the pavilion main facets as represented by R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, and R.sub.8 are at a depth of 1.05 R1, 1.04 R1, 1.04 R1, 1.05 R1, R1, 1.07 R1 and 1.07 R1. The girdle depth at which the common interphase between pairs of short half facets intersect the cable (RR) as represented by R.sub.1, R.sub.2, V.sub.1, R.sub.4, R.sub.5, R.sub.6 and R.sub.8 are at 1.03 R1, 1.05 R1, 1.03 R1, 1.04 R1, 1.03 R1, 1.01 and 1.01 R1. The girdle depth at which the common interphase between pairs of short half facets (T.sub.1, T.sub.16) emerges to the pavilion surface, from which point (V.sub.1) 1.sup.st pavilion angles are cut and chiselled along a cable to the 1.sup.st points of the nesting pavilion main facets (O.sub.1 and O.sub.8) is R.sub.1. In order to obtain a shape of the heart without the indent, the gemstone is cut and chiselled for the girdle depth of the 1.sup.st pavilion short half angle of the pavilion lower half facets with the 1.sup.st common interphase (P) on the axis line at R.sub.7 to be about 1.07 R1.

[0082] These cuts are best viewed in gemstones having a minimum size of 10 cents. These facets can be hand cut and chiseled by a skilled workman in large size diamonds. In smaller size diamonds, the invention as disclosed are usually machine cut using computer algorithms based on the disclosed invention.

[0083] When viewed from the table facet the gemstone as described above, the cable joining the 1.sup.st points in the gemstone, form an outline of a heart shape (Z) along a horizontal plane. (FIG. 7, FIG. 14)

[0084] The above method is preferable applied to a gemstone like a diamond, which with its high refractive index, and the various intricate facet cuts as described above, could portray brilliance, even in ordinary light.