One variation of a diamond composition includes carbon: including a first amount of carbon-13 isotopes and a second amount of carbon-12 isotopes; and sourced from a hydrocarbon mixture including hydrocarbons and formed via methanation of a carbon dioxide mixture. The carbon dioxide mixture: sourced from a sample of air including carbon dioxide and impurities; conveyed through a separation unit configured to remove impurities; including carbon dioxide and impurities; conveyed through a distillation column configured to regulate amounts of carbon-13 isotopes and carbon-12 isotopes; and exhibiting a target ratio of carbon-13 isotopes to carbon-12 isotopes at an outlet of the distillation column. The diamond composition: formed via chemical vapor deposition; and exhibiting an isotopic signature defining a final ratio of the first amount of carbon-13 isotopes to the second amount of carbon-12 isotopes within a first target range corresponding to the target ratio exhibited by the carbon dioxide mixture.

A grey gold alloy which is nickel-free, cobalt-free, iron-free, silver-free, copper-free, zirconium-free, niobium-free, chromium-free and manganese-free, including, expressed in weight percent, from 75.0 to 76.5% of Au, from 15 to 23% of Pd, from 0.5 to 5% of Rh, from 0 to 7% of Pt, and from 0 to 5% of at least one of the alloying elements Ir, Ru, Ti, In, Ga, B and Re, the respective percentages of all the alloying elements adding up to 100%.

The invention relates to a cemented carbide composition producing method for precious metal, which includes a titanium nitride component contained therein and shows excellent workability, corrosion resistance, reduction in weight and other desirable mechanical properties, as well as the low amount of nickel used as a metallic binder and an aluminum oxide coating helps to suppress potential negative skin reactions.

A jewelry item includes a thin piece member formed from a gold alloy containing gold (Au) as a first metal element and a second metal element other than gold (Au), a frame member including a third metal element other than the first metal element and the second metal element and a fourth metal element as a metal for an alloy of the third metal, forming a bond with and surrounding a peripheral edge of the thin piece member, and a compound layer containing the first metal element, the second metal element, the third metal element and the fourth metal element is interposed between the thin piece member and the frame member.

A jewelry item includes a thin piece member formed from a gold alloy containing gold (Au) as a first metal element and a second metal element other than gold (Au), a frame member including a third metal element other than the first metal element and the second metal element and a fourth metal element as a metal for an alloy of the third metal, forming a bond with and surrounding a peripheral edge of the thin piece member, and a compound layer containing the first metal element, the second metal element, the third metal element and the fourth metal element is interposed between the thin piece member and the frame member.

A bracelet having articulated links, including an articulation between a first link and a second link including a tongue that pivots in an opening between side flanges of this first link together forming a double clevis fitting, wherein, in the articulation, the first link or respectively the second link includes at least one external trunnion or respectively at least one internal trunnion arranged to pivot in an internal half-bearing of the second link, or respectively in an external half-bearing of the first link, the second link or respectively the first link includes at least an upper part and a lower part arranged to enclose and conceal therebetween each external trunnion or respectively each internal trunnion.

A method for assembling a stone on a setting support, the stone being cut to exhibit a table, a crown, a girdle and a pavilion, including the steps of: providing a substrate coated with a pattern including an electrically conductive layer covered with a resin layer, the pattern having an inner contour delimiting a hole through the coated substrate and an outer contour corresponding to the outer contour of the desired setting support; removing the resin layer; after dissolution of the resin layer, positioning the stone in the through hole, the stone resting on the electrically conductive layer; and electrodepositing a metal layer on the electrically conductive layer to form the setting support, in order to make the stone integral with the metal layer.

A method for assembling a stone on a setting support, the stone being cut to exhibit a table, a crown, a girdle and a pavilion, including the steps of: providing a substrate coated with a pattern including an electrically conductive layer covered with a resin layer, the pattern having an inner contour delimiting a hole through the coated substrate and an outer contour corresponding to the outer contour of the desired setting support; removing the resin layer; after dissolution of the resin layer, positioning the stone in the through hole, the stone resting on the electrically conductive layer; and electrodepositing a metal layer on the electrically conductive layer to form the setting support, in order to make the stone integral with the metal layer.

Disclosed herein are synthetic, or cultured diamonds which have at least one artificially embedded inclusion(s) incorporated within their crystal structure during the diamond's deposition or growth process. Disclosed are cultured diamonds having a substrate portion, artificially embedded inclusion(s) disposed on the substrate portion, and an encapsulating portion, formed on the artificially embedded inclusion(s). The substrate portion and the encapsulating portion are bonded together by covalent carbon to carbon bonds.

Disclosed herein are synthetic, or cultured diamonds which have at least one artificially embedded inclusion(s) incorporated within their crystal structure during the diamond's deposition or growth process. Disclosed are cultured diamonds having a substrate portion, artificially embedded inclusion(s) disposed on the substrate portion, and an encapsulating portion, formed on the artificially embedded inclusion(s). The substrate portion and the encapsulating portion are bonded together by covalent carbon to carbon bonds.