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.

A patterned diamond and methods of making such patterned diamond are disclosed. The patterned diamond may include: a single crystal diamond or a polycrystal diamond; and a metallic pattern embedded in the single crystal diamond or the polycrystal diamond such that, the single crystal diamond or the polycrystal diamond encapsulates the metallic pattern from at least 4 sides. The disclosed method may include providing a first portion of a single crystal diamond or a polycrystal diamond; introducing a metallic pattern to at least one surface of the first portion of the single crystal or a first portion of the polycrystal diamond; and growing, using a CVD process or HTHP process, a second portion of the single crystal diamond or the second portion of the polycrystal diamond on the first portion, such that the single crystal diamond or the polycrystal diamond at least partially encapsulates the metallic pattern.

A gemstone cut into a round stone and method of cutting a gemstone are disclosed herein. More particularly, methods and systems for preparing gemstones having enhanced brilliance or for enhancing the brilliance of previously cut gemstones, and to the gemstones prepared are described herein.

The invention relates to a decorative part (1, 3, 5) including several stones (2) and a device (7, 7, 47, 47) for securing the stones (2) in relation to each other. According to the invention, the securing device (7, 7, 47, 47) includes a single electrodeposited base (9, 9, 49, 49) whose shape matches one part of the stones, thus allowing all the stones (2) to be attached in relation to each other without any stress, and the girdles (6) of the stones (2) are mounted edge-to-edge in relation to each other so that the single base is concealed. The invention also relates to the method for manufacturing a part (1, 3, 5) of this type.

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.

A gemstone includes a crown, a pavilion, and a girdle disposed between the crown and the pavilion. The girdle has a pear-shaped cross-section with a rounded end a tapered end narrower than the rounded end. 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 method for manufacturing a jewel of the polycrystalline type, in particular for a timepiece, the jewel including, for example, poly-ruby of the type al2O3Cr or Zirconia of the type ZrO2, the method including a first step of producing a precursor, and a second step of pressing the precursor in order to form a body, the pressing being carried out using a pressing device provided with an upper die and a lower die defining a pressing space in which the precursor is disposed, the device being provided with a wire passing through at least part of the lower die to open out into the pressing space, the lower die being capable of sliding about the wire, the pressing taking place by bringing the lower die and the upper die closer to one another to form a body comprising a bottom face provided with a hole.