The invention relates to the field of jewelry, specifically to a diamond with eighty-one facets having a ten hearts and ten arrows inner structure and a cutting method thereof. The diamond comprises a table facet, ten main crown facets and ten main pavilion facets; a crown star facet is disposed at a junction of two adjacent main crown facets with the table facet; a crown small facet is disposed at a junction of two adjacent main crown facets with the crown star facet; a small sector is disposed at a junction of the main crown facet with the crown small facet; and two main pavilion facet auxiliary surfaces are disposed at a junction of two adjacent main pavilion facets. The cutting method comprises a division of a pavilion, a crown and a girdle, the pavilion cutting and the crown cutting. The shaped diamond has very good brilliance, fire and sparkle.

A gemstone includes a crown, a pavilion, and a girdle disposed between the crown and the pavilion. The girdle has an elliptical cross-section with a major axis and a minor axis. The surface of the gemstone is generally divided into a number of groups of interlocking facets disposed at a variety of angles. The groups of facets comprising the surface of the crown generally include star facets, upper intermediate crown facets, lower intermediate crown facets, main crown facets, and upper girdle facets. The upper girdle facets generally abut an upper edge of the girdle. The groups of facets comprising the surface of the pavilion include culet-adjacent facets, candle facets, main pavilion facets, and lower girdle facets. The lower girdle facets generally abut a lower edge of the girdle.

A gemstone includes a crown, a pavilion, and a girdle disposed between the crown and the pavilion. The girdle has an elliptical cross-section with a major axis and a minor axis. The surface of the gemstone is generally divided into a number of groups of interlocking facets disposed at a variety of angles. The groups of facets comprising the surface of the crown generally include star facets, upper intermediate crown facets, lower intermediate crown facets, main crown facets, and upper girdle facets. The upper girdle facets generally abut an upper edge of the girdle. The groups of facets comprising the surface of the pavilion include culet-adjacent facets, candle facets, main pavilion facets, and lower girdle facets. The lower girdle facets generally abut a lower edge of the girdle.

A round stone is intended for being inserted contiguously with other similar stones to as to conceal the setting of the stones. Facets are bevel-formed between the girdle and the pavilion. Grooves, open at the two ends thereof, are formed, as by sawing in a plane perpendicular to the axis, in the facets to receive the setting claws.

A decorative element comprising a faceted transparent body having a front surface and a back surface, and a coating on at least part of the back surface of the faceted transparent body. The coating comprises a reflective layer of semiconductor material and a layer of lacquer over the reflective layer, and the reflective layer of semiconductor material has a thickness of at least about 400 nm or at least about 250 nm. Methods of making a decorative element, uses of the decorative element, a switch cover comprising the decorative element, and a switch comprising a sensor for detecting actuation of the switch and a cover protecting the sensor and comprising the decorative element are also described.

Incident light enters a faceted gemstone and is routed along optical paths to exit the gemstone as emergent light. At least one diffraction grating is patterned on the gemstone in an asymmetrical manner relative to an axis of symmetry. The diffraction grating has a diffractive structure positioned on at least one facet for diffracting the light being routed along at least one of the optical paths to enhance color dispersion of the emergent light. The diffraction grating is the only diffraction grating to diffract the light being routed along the at least one optical path to diminish haze of the emergent light.

The invention relates to a gemstone cut, comprising a crown having a flat table and main crown facets (10-12) being arranged around the table (1) and being inclined relative to the table, a girdle (5) at which the gemstone has its largest transverse dimension, and a pavilion adjoining the girdle from below the girdle and having main pavilion facets (7) around the girdle, whereby the number of the main pavilion facets is odd. The invention also relates to an article comprising a gemstone according to the invention and a method for improving the optical properties of a gemstone.

The present invention provides a gemstone comprising a girdle dividing the gemstone into a pavilion and a crown having a table surface; a tier of facets cut into the pavilion at a position immediately below the girdle; and a continuous groove. The groove facilitates mounting to a collet having a mounting rim. The continuous groove is located in the tier of the facets cut into the pavilion. The placement of the tier of facets and continuous groove does not obstruct light return.

The invention discloses a round or a heart shaped gemstone (FIG. 1) (FIG. 8) visually encompassing a heart shape (FIG. 7,15:AD) within, and its method of manufacture. The gemstone comprises of an upper double crown table facet (A), a lower pavilion (C) with a culet (D) at its lower tip, and a girdle (B) separating the upper crown table facet from the pavilion. The pavilion (FIG. 1) comprises of pavilion main facets, lower girdle facets and short half facets. The short arms (P) of the kite shaped pavilion main facets meet at the culet, long arms (Q) meet at 1.sup.st points (R) and the short arms and long arms of each pavilion main facet meet at 2.sup.nd points (S) at specific girdle depths. The lower girdle facets (L) and the respective short half facets (T) are faceted from the lower girdle facets at 1.sup.st pavilion angles along a cable (R) joining the 1.sup.st points. The 2.sup.nd pavilion short half angles (Z) along a cable joining the 2.sup.nd points of the pavilion main facets are less than the 1.sup.st pavilion angles. The girdle depth of the 1.sup.st point of one pair of symmetrical pavilion main facets is 0.5% to 10% less than the remainder pavilion main facets.

Aspects of the invention may be directed to a method of creating a predetermined structure from a diamond bulk. In some embodiments, the method may include: irradiating the diamond bulk with at least one laser having a focal point at a predetermined location, the laser may create graphitization at locations where the focal point of the laser engages the diamond bulk; at least one of: moving the diamond bulk to be positioned with the focal point of the laser within the diamond bulk, and moving the at least one laser such that diamond bulk be positioned with the focal point of the laser, along at least one axis wherein the movement corresponds to a predefined scheme; removing of the graphite from the diamond bulk; and extracting the predetermined structure from the diamond bulk.