A sparkling, oblong-shaped precious stone, such as an emerald or cushion cut diamond is formed by a planar table facet, a girdle, two pairs of long crown facets located between the table facet and the girdle, and the two pairs of long pavilion facets located between the base of the stone and the girdle.

Provided is a gemstone treated with a cut expressing a reflected image pattern not recognized before, wherein the gemstone includes the crown 100 having the table 110 and plural bezel facets 130, and the pavilion 200 having the culet 210 and plural main facets 220; the girdle 300 is formed between the crown 100 and the pavilion 200; a direction of a horizontal component of an inclination direction of the bezel facet 130 from the table 110 to the girdle 300 is set to be different from a direction of a horizontal component of an inclination direction of the main facet 220 from the culet 210 to the girdle 300; and inclination angles of the bezel facet 130 and the main facet 220 are set so that a light that enters the table 110 is reflected by two of the main facets 220 and emitted from the bezel facet 130.

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.

A gemstone includes a crown, a pavilion, and a girdle disposed between the crown and the pavilion. 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 main crown facets, upper intermediate crown facets, lower main crown facets, lower intermediate 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, lower candle facets, lower main pavilion facets, upper candle facets, upper 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 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.

The present disclosure relates to the field of Chemical Vapor Deposition (CVD) diamonds and their processing after fabrication. In particular, the present disclosures provides a method for coring and slicing a CVD diamond product, wherein the CVD diamond product comprises a CVD diamond and graphitized material covering several side-faces of the diamond. The method is carried out by an apparatus that provides a laser beam coupled into a fluid jet. The method comprises, for the coring, cutting the product with the laser beam to remove the graphitized material from the side-faces of the diamond. Further, the method comprises, for the slicing, cutting off one or more slices from the diamond with the laser beam.

Presented herein is a diamond comprising a table, a crown, a girdle, a pavilion, and a culet. The table is rectangular, having a length and a width. The table includes a first side, adjacent to a second side, adjacent to a third side, and adjacent to a fourth side. The first side of the table is directly connected with a first facet of the girdle. The second side of the table is directly connected with a second facet of the girdle. The crown includes a plurality of facets connecting the third side and the fourth side of the table to the girdle. The pavilion is connected to the girdle. The culet is positioned directly below a point having a 1% deviation from the center of the girdle.

An apparatus for automated polishing of an object with multiple facets includes a polishing wheel, a robotic arm, a sensor and a controller. The robotic arm positions the object in contact with the polishing wheel. The sensor senses a polishing related parameter during polishing of the object with the polishing wheel. The controller operates the robotic arm to rotate the object about an axis perpendicular to the polishing wheel, receives a sensing signal from said sensor at different orientations of said object during polishing and selects a polishing orientation from the different orientations based on said sensing signal.

A method of determining an optimal target gemstone to be obtained from a rough gemstone comprises obtaining a first series of 2D images of the rough gemstone; providing a 3D model of a target gemstone to be obtained from the rough gemstone; and generating a second series of 2D images of the target gemstone from the 3D model thereof. The method then comprises comparing the first and second series of 2D images to determine an optimal transformation to be applied to the 3D model of the target gemstone.