The present invention is directed to a formulation of one or more low silver containing alloys (including those with silver content below 50 weight %, w %) that show one of the group of distinct pink, yellow and green colors and further demonstrate enhanced resistance to tarnish and other beneficial features described herein.

The present invention is directed to a formulation of one or more low silver containing alloys (including those with silver content below 50 weight %, w %) that show one of the group of distinct pink, yellow and green colors and further demonstrate enhanced resistance to tarnish and other beneficial features described herein.

The present invention is directed to a jewelry element which includes two layersa cladding layer and a substrate layer, each layer being its own alloy. The cladding layer and the substrate layer each include a base metal such as silver or gold at the same percentages so that the resulting jewelry element can be labeled in accordance with one or more industry-wide requirements. The cladding layer is further enhanced by introduction of a metal providing additional hardness when included in the alloy. By limiting the hardness metal or metals to being deposed only in the cladding layer, less of the hardness metal need be used, thereby reducing cost yet retaining the requisite hardness characteristic. Each of the alloys may further contain other metals for any of a number of reasons, including but not limited to, tarnish resistance.

Nickel-free austenitic stainless steel comprising, in mass percent: chromium in amounts of 10<Cr<21%; manganese in amounts of 10<Mn<20%; molybdenum in amounts of 0<Mo<2.5%; copper in amounts of 0.5Cu<4%; carbon in amounts of 0.15<C<<%; nitrogen in amounts of 0<N1, and
the remainder being formed by iron and any impurities from the melt.

The present invention is directed to a jewelry element which includes two layersa cladding layer and a substrate layer, each layer being its own alloy. The cladding layer and the substrate layer each include a base metal such as silver or gold at the same percentages so that the resulting jewelry element can be labeled in accordance with one or more industry-wide requirements. The cladding layer is further enhanced by introduction of a metal providing additional hardness when included in the alloy. By limiting the hardness metal or metals to being deposed only in the cladding layer, less of the hardness metal need be used, thereby reducing cost yet retaining the requisite hardness characteristic. Each of the alloys may further contain other metals for any of a number of reasons, including but not limited to, tarnish resistance.

Hardened cobalt alloys for forming jewelry, including finger rings as well as methods and processes for producing such alloys. In one illustrative embodiment, such an alloy can contain cobalt in an amount of from about 35 wt % to about 65 wt %, in combination with chromium in an amount of from about 16 % wt to about 32 wt %, and molybdenum in an amount of from about 8 wt % to about 31 wt %. Aluminum, silicon, boron, titanium, and other hardness enhancing materials may also be present. Hot investment casting may be used to form items from the alloys, which may then be shaped or polished to a final form. Annular finger rings constructed from these materials may have a white appearance similar to white gold or platinum, may have increased resistance to scratching compared to traditional cobalt chromium rings, and may be easily be removed by cracking in an emergency situation.

A timepiece or piece of jewellery or gemstone jewellery made of a zinc-free, germanium-free, nickel-free, cobalt-free, indium-free gold alloy, the alloy containing, in weight percent, between 75% and 77.5% of gold, between 0.5% and 3% of palladium, between 10% and 18% of silver and between 5% and 13% of copper, wherein the respective percentages of all the alloying elements add up to 100%.

The present invention is directed to a formulation of one or more low silver containing alloys (including those with silver content below 50 weight %, w %) that show one of the group of distinct pink, yellow and green colors and further demonstrate enhanced resistance to tarnish and other beneficial features described herein.

An improved sterling silver alloy. Like all sterlings, the improved alloy is at least 92.5 percent silver by weight. It has less copper than traditional sterlings: 3.0 percent versus the traditional 7.5 percent. Additionally, the improved alloy includes about 2.75 percent palladium, about 1.0 percent tin, and about 0.75 percent zinc, all by weight. A grain refiner, such as ruthenium, may also be provided. The components of the preferred alloy are melted, degassed, remelted, and then formed into casting grains, wire, and etc. The resulting alloy is significantly harder, as cast, than traditional sterlings: 95-120 Vickers versus 65 Vickers for traditional sterlings. The improved alloy also exhibits improved corrosion resistance. Other than a slightly higher (<200 F) liquidus temperature, the improved alloy may be worked in substantially the same manner as traditional sterlings. Pieces cast from the improved alloy may be age hardened to about 160 Vickers, if desired.

The present invention relates to a method for manufacturing a timepiece or jewellery component from a material comprising at least 18 carats of gold, comprising the following steps: a) producing Au@metal oxide nanoparticles, step a) comprising at least the sub-steps of a1) synthesising gold nanoparticles that have dimensions and shapes giving them a plasmonic effect; aa2) mixing the gold nanoparticles from step a1) with a surfactant comprising functional groups for coupling to the metal oxide, while maintaining a plasmonic effect; a3) forming the metal oxide shell, while maintaining a plasmonic effect; b) producing a semi-finished product from a material comprising at least 18 carats of gold using the Au@metal oxide nanoparticles from step a), while maintaining a plasmonic effect, the semi-finished product having a colour such that the difference E in the CIE Lab colour space between the colour of the obtained semi-finished product and the colour of the Au@metal oxide nanoparticles formed in step a), in the dry state, is less than 10; and c) producing the timepiece or jewellery component from said material comprising at least 18 carats of gold using the semi-finished product obtained in step b), while maintaining a plasmonic effect.

The present invention also relates to a timepiece or jewellery component obtained by the manufacturing method as defined above, said timepiece or jewellery component being obtained using a semi-finished product that has a colour defined in the CIE L*a*b space by the parameters 5<a*<5, 5<b*<5 and L*<15.