The invention relates to a field of gemstones and more specifically to round cut and heart shaped gemstones, where in such gemstone encompasses the shape of a heart within its body.
A gemstone quality is usually assessed by its carat value, color, clarity, brilliance, light penetration, cut and shape. In addition to these attributes, a gemstone like a diamond's quality is assessed by its symmetry and reflective quality, which is a result of a diamond's cut which affects and potentially enhances all the mentioned characteristics. The cut on the facets determines how well a diamond “performs,” in other words, how well it reflects light under a variety of lighting conditions and situations, and more importantly how they perform in more natural lighting situations. Round diamonds have all the facets in a tier cut to the same angle, which is close to the ideal in terms of brilliance and dispersion. The sophistication of diamond cutting is able to match the new demands among wealthy customers for more unique diamond forms and hence there are challenges to bring in newer innovations, in respect of cuts, appearance and shapes, that give a novel effect, which are a result of innovative cutting, and which do not compromise on brilliance and dispersion.
U.S. Pat. No. 8,813,519 B2 discloses a modified princess cut diamond and a method of forming a modified princess cut diamond into a symmetrical shape possessing a radiating heart and arrows pattern characteristic of the true hearts and arrows pattern in a round cut diamond. However, these heart and arrow pattern cannot be normally seen by the naked eye, and result from the reflection of the facets and not as a result of calculated facet cuts of the diamond. The cuts as described in the aforesaid patent have been bought about by forming reflecting images in the table facet. Further, the invention disclosed in the afore referred patent does not reveal or disclose an invention, where in the gemstone would give the effect of a heart within a round cut or heart shape, and makes it appear as if a heart shaped gem is placed within the gemstone. The image of a gemstone within a gemstone requires not only mere precision, but innovation in cutting the facets, and the angles of the facets in relation to each other. These depend on the shape of the gemstone, i.e. whether they are round cut, cushion cut, princess cut or heart shape.
The present invention discloses for the first time, a series of facet cuts by which a heart shape design can be seen within a round diamond or a heart shaped diamond, from the pavilion (Bottom side) and the Crown (Top side) with the naked eye. Because of the specific facet cuts along the pavilion, it gives the appearance of a gemstone within another gemstone. These facets produce the visual effect of a heart shape diamond inside a round diamond and heart shaped diamond.
In the main aspect of the invention, a gemstone visually encompasses a heart shape design within. The invention uses a gemstone comprising an upper double crown table facet, a lower pavilion with a culet at its lower tip, a girdle separating and distinguishing the upper crown table facet from the pavilion, and girdle main facets around the girdle. In furtherance of the objective of the invention, there are a plurality of pavilion facets below the girdle facet comprising of lower girdle facets, the short half facets and pavilion main facets. The kite shaped pavilion main facets emerge upwardly from the culet. The short arms of the kite shaped facet meet at the culet and long arms meet at 1st points which are at a girdle depth ranging from 70 to 85% of the girdle depth. The short arms and long arms of each pavilion main facet meet at 2nd points at depths ranging from 80 to 96% of the girdle depth. The lower girdle facets, which are substantially triangular emerge downwardly from the girdle. Substantially triangular short half facets are faceted from the lower girdle facets along a cable joining the 1st points. The lower girdle and the corresponding short half facet have a common vertex at 2nd points, pointing towards the culet. Pairs of short half facets alternate the long arms of the pavilion main facets. The girdle facet angle is in the range of 30° to 60°. The 1st pavilion short half angles, are formed along a cable joining the 1st points. The 1st pavilion short half angles are 0.01° to 8° less than the girdle facet angle. The 2nd pavilion short half angles are formed along a cable joining the 2nd points of the pavilion main facets, such that the 2nd pavilion short half angle is 0.01° to 8° less than the 1st pavilion short half angle. In a table view or pavilion view, the pavilion facets all appear to be arranged around the central culet on either side of an axis line along the horizontal plane.
In a further aspect of the invention, the gemstone is round, with the table facet comprising of 16 upper crown-1 facets, 16 upper crown-2 facets, 8 crown main facets and 8 star facets.
In another aspect of the invention the gemstone is heart shaped having a notch and an oppositely located apex. The table facet comprises of 16 upper crown-1 facets, 16 upper crown-2 facets, 9 crown main facets and 8 star facets.
In yet a further aspect of the invention the gemstone as has 4 to 12 pavilion main facets, and double the number of lower girdle facets and short half facets.
In an ideal aspect of the invention, the gemstone is a diamond and has 4 pairs of pavilion main facets and 8 pairs of short half facets and lower girdle facets, each facet being symmetrical with its corresponding facet pair across the axis line. The heart shaped gemstone has a girdle facet angle in the range of 43° to 48° at the girdle depth of 78% to 82% and the angle of variance between the 2nd pavilion short half angle at the 2nd point at a depth of 88.5% to 94% and the 1st pavilion short half angle in the range of 38° to 42° at 1st point at a depth of 82% to 85% is 0.3° to 5.0°. The angle variance between the girdle facet angle and the 1st pavilion short half angle is in the range of 1° to 7°. In a round gemstone, the girdle facet angle is in the range of 40° to 46° at the girdle depth of 78% to 82%. The angle variance between the 2nd pavilion short half angle at the 2nd point at a depth of 88.5% to 94% and 1st pavilion short half angle at 1st point at a depth of 82% to 85% is in the range of 0.5° to 5°. The angle variance between the girdle facet angle and the 1st pavilion short half angle is in the range of 1° to 5°.
In an interesting aspect of the invention, a pair of symmetrical short half facets having one common side along the axis line, have sides opposite the vertex meet at a facet depth approximately midway between the 1st point and the 2nd point relevant to the short half facet pair. A second pair of symmetrical short half facets also having one common side along the same axis line, have the second vertex at a common point on the cable and axis line, such vertex being at a girdle depth equivalent to the girdle depth of the 1st point of the longest pavilion main facet with a variance of not more than 15%.
Yet another aspect of the invention, relates to the method of making a gemstone encompassing the shape of a heart along the horizontal plane of the gemstone. The invention is worked on a gemstone with an upper double crown table facet, a lower pavilion with a culet at its tip, a girdle with girdle main facets, separating and distinguishing the pavilion from the crown table facet. The pavilion has pavilion facets with at least four pairs of lower girdle facets extending downwardly from the girdle to the culet, which in the table view or pavilion view appear to be arranged around the culet on either side of an axis line traversing the horizontal plane of the pavilion. In case of a heart shape diamond, the axis line passes through the notch and apex of the heart shape.
In the working aspect of this invention, the lower girdle facets are cut, chiselled and polished such that the lower girdle angle, at girdle depth of 65% to 85%, is in the range of 30° to 60°. The lower girdle facets are further cut and chiselled to have at least two pairs of symmetrical kite shaped pavilion main facets with a pair of short arms and long arms, such that the short arms meet at the culet, long arms meet at 1st points at a facet depth in the range of 70% to 85%, and the short arm and the long arm meet at 2nd points at facets depth in the range of 80% to 96%. The common vertices of adjacent pairs of the lower girdle facets are at the girdle depth of the 2nd points, after the pavilion main facets are cut. A pair of pavilion main facets, not having a common side along the axis line are first cut such the girdle depth of the 1st point of this pavilion main facet is 0.5% to 10% less than the other pavilion main facets. A pair of pavilion short half facets are cut and chiselled from a pair of lower girdle facets having a common side along the axis line, along the pavilion surface of the gemstone from a point along the axis line at a girdle depth equivalent to the pair of pavilion main facets having 1st points with the least girdle depth, at 1st pavilion angles along a cable connecting the 1st points of the pavilion main facets flanking such pair of pavilion short half facets. The remainder lower girdle facets are further cut, chiselled and polished at 1st pavilion angles along a cable connecting the 1st points of all pavilion main facets, to form substantially triangular short half facets, the 1st pavilion angles being at least 0.01 to 8.0° less than the lower girdle angle. The lower girdle facet and the corresponding short half facets have a common vertex at the respective 2nd points. The pavilion main facets of the gemstone are further cut chiselled and polished along a cable joining the 2nd points to form 2nd pavilion short half angles, such that the 2nd pavilion short half angle is at least 0.01 to 8° less than the 1st pavilion short half angle. The gemstone may be round or heart shaped.
In an ideal aspect of the invention relating to the method of obtaining a perfect heart shape design within the gemstone, the gemstone is cut, chiselled and polished to have 4 symmetrical pairs of pavilion main facets, 8 pairs of symmetrical lower girdle facets and 8 pairs of symmetrical short half facets, each facet in symmetry with the corresponding facet on the opposite side of the axis line. The 1st pavilion short half angles at 1st points with facet depth ranging from 80-84.5%, is 2° to 8.0° less than the lower girdle facet angle, and further the 2nd pavilion short half angle at a facet depth of 91% to 94% is 0.25° to 5° less than the 1st pavilion short half angle.
In the final aspect of this invention, a pair of symmetrical adjacent short half facets with a common side along the axis line are prior cut and polished to have sides opposite the vertex at the 2nd point converging at a girdle depth approximately midway between the 1st point and the 2nd point.
This forms a heart shape design with notch and apex as seen from the table view or pavilion view.
a: Crown top side angle view of round cut gemstone
In its main embodiment the invention describes a uniquely cut double crown gemstone preferably round cut (
As seen in
The crown angles on the upper double crown table are at recommended angles as seen in
The crown angles are determined by viewing the diamond from a side profile and visually estimating the angle of the top portion of the diamond. In respect of a round diamond, the upper crown-1 angle cut is in the range of 35° to 48° and the respective preferred azimuth edge of the upper crown-1 facets are 11.25°, 33.75°, 56.25°, 78.75°, 101.25°, 123.75°, 146.25°, 168.75°, 191.25°, 213.75°, 236.25°, 258.75°, 281.25°, 303.75°, 326.25°, 348.51°. The Upper Crown 2 facets are at an angle in the range of 35° to 48°. Upper Crown 2 facets are optional. Upper Crown 2 facets add more brightness to the stone. The Main crown facets are at an angle of 30° to 38° in relation to the upper crown 1 facet and the star facets are placed at 15° to 30.° in relation to the central table. In respect of a heart shape diamond, the upper crown-1 angle cut is in the range of 35° to 48° and the preferred azimuth edge of the upper crown-1 facets are 6.5°, 29°, 41.5°, 52.5°, 63.10°, 116.9°, 127.4°, 138.5°, 151°, 173.5°, 207.5°, 245.7°, 267.4°, 272.6°, 294.2°, 332.4° respectively. The Upper Crown 2 facets are at an angle in the range of 35° to 48°. and the preferred azimuth edge of the upper crown-2 facets are 6.59°, 28.89°, 41.55°, 52.49°, 63.19°, 116.79°, 127.49°, 138.43°, 151.00°, 173.39°, 207.59°, 244.90°, 267.99°, 271.99°, 294.99°, 332.39° respectively, Upper Crown 2 facets are optional. Upper Crown 2 facets add more brightness to the stone. The Main crown facets comprise of a pair of substantially triangular crown curve facet (G′) at an angle of 30 to 38° at an azimuth edge of 25° & 155.0°; a pair of four sided crown head-1 facet (G″) and a pair of four sided crown head-2 facet (G′″) at an angle of 32 to 40° at an azimuth edge of 233°, 256°, 284°, 307°; a pair of four sided crown wing facet (G″″) at an angle of 33° to 40° and at a preferred azimuth edge of 47° & 133°, and one kite shaped crown point facet (G′″″) at an angle of 30° to 42° in relation to the central table at 15° to 30.° in relation to the central table (J) at an azimuth edge of 36.45°, 61.78°, 118.20°, 143.54°, 192.85°, 256.33°, 283.65°, 347.13°. No claim is being made in respect of the crown angles or the crown table.
As seen in
In a pavilion view, (
In another embodiment of this invention, the gemstone has in addition to the table facet as described above, 12 to 24 lower girdle facets, 12 to 24 short half facets and 4 to 12 pavilion main facets.
The preferred facet azimuths for the girdle facets, 1st pavilion short half angle and 2nd pavilion short half angle for a round cut diamond, for an improved embodiment having 16 lower girdle facets, 16 short half facets and 8 pavilion main facets, with the 1st point of the pair of pavilion main facets (O3,O6) having the shortest girdle depth immediately adjacent to the pavilion mains (O4,O5) nestling the small pavilion short half facets. is given in Table II below:
The preferred facet azimuths for the girdle facets, 1st pavilion short half angle and 2nd pavilion short half angle for an improved embodiment having 16 lower girdle facets, 16 short half facets and 8 pavilion main facets, with the 1st point of the pair of pavilion main facets (O3,O6) having the shortest girdle depth immediately adjacent to the pavilion mains (O4,O5) nestling the small pavilion short half facets. for a heart shape diamond is given in Table III below
The facet azimuths mentioned in the table are indicative of the preferred azimuth, and could vary in the range of +/−15°.
As seen in FIGS. (4) and (11), the pavilion facets (L, T, O) are symmetrical with the corresponding pavilion facets on the other side of the axis line (C′).
In round cut gemstone, there is a consistency in the girdle angles, 1st pavilion short half angles and 2nd pavilion short half angles, subject to minor variations in the range of +/−1°. In respect of heart shaped gemstones, the facets are further cut, chiselled and polished such that there is a variation in the girdle facet angles of adjacent lower girdle facets in the range of 0° to 2°. Likewise there is a variation in the 1st pavilion short half facet angles of adjacent short half facets in the range of 0° to 3.5°, and in 2nd pavilion short half facet angles in the range of 0° to 3°. This addresses the asymmetry in a heart shaped gemstone, to enable the making of a gemstone encompassing a heart shape within. Table IV below gives the angle range of the girdle facet angle, 1st pavilion short half angle and 2nd pavilion short half angle, which would enable a heart shaped design to be produced within the gemstone.
Table V below gives the percentage depth at which the lower girdle facets, short half facets and pavilion main facets, the 1st pavilion short half angle and the 2nd pavilion short lower half angle with reference to the girdle are cut, where girdle is considered as 0 and culet as 100.
In a more precise embodiment of the invention, the gemstone has 16 lower girdle facets, 16 short half facets and 8 pavilion main facets and the facet depth at the 1st point ranges from 82-85%, and the facet depth at the 2nd point ranges from 88.5 to 96%, with angles of variance among the facets as mentioned above.
This invention could be applied to any gemstone where the hardness is over 5, but it is best applied in a diamond, where because of the brightness, lustre and fire, as a result of the cuts on the table facet, the heart shape is perfectly seen inside the diamond, giving the effect of one diamond being inset in another diamond.
Number | Date | Country | Kind |
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201723014425 | Apr 2017 | IN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/IN2018/050187 | 4/3/2018 | WO | 00 |