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US 11,889,904 B2Granted
Discoloration resistant gold alloy and method of production thereof
AssigneeArgor-Heraeus SA
InventorsSergio Arnaboldi, Marta Rossini, Marco Nauer
Life of this patent
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Abstract
A discoloration resistant Gold alloy for jewelry characterized in that it comprises in weight: Gold, in the amount comprised between 755‰ and 770‰, Copper, in the amount comprised between 165‰ and 183‰, Silver, in the amount comprised between 28‰ and 50‰, Palladium, in the amount comprised between 19‰ and 23‰ and Iron, in the amount comprised between 2‰ and 6‰. and characterized by the absence of Vanadium.
Claims11
A Gold alloy for jewelry, consisting of, in weight:
- Gold, in the amount comprised between 755‰ and 770‰,
- Copper, in the amount comprised between 165‰ and 183‰,
- Silver, in the amount comprised between 28‰ and 50‰,
- Palladium, in the amount comprised between 19‰ and 23‰ and
- Iron, in the amount comprised between 2‰ and 6‰,
- the Gold alloy being free of Vanadium;
- the Gold alloy having a color that, on the CIE 1976 color chart, and measured according to ISO DIS 8654 standard with a 2° observer, has an a* coordinate comprised in the interval 5÷8, and a b* coordinate comprised in the interval 13.5÷15.5 and has a nominal color difference ΔE (a*, b*)>3.24 and ΔE (L, a*, b*)>3.57 with respect to the nominal color of the ISO DIS 8654:2017 5N alloy.
4 more elements
A Gold alloy for jewelry, consisting of, in weight:
- Gold, in the amount comprised between 755‰ and 770‰,
- Copper, in the amount comprised between 165‰ and 183‰,
- Silver, in the amount comprised between 28‰ and 50‰,
- Palladium, in the amount comprised between 19‰ and 23‰ and
- Iron, in the amount comprised between 2‰ and 6‰,
- one or more of Iridium, Ruthenium, Rhenium, a sum of Iridium, Ruthenium, Rhenium being not higher than 2‰
- the Gold alloy having a color that, on the CIE 1976 color chart, and measured according to ISO DIS 8654 standard with a 2° observer, has an a* coordinate comprised in the interval 5÷8, and a b* coordinate comprised in the interval 13.5÷15.5 and has a nominal color difference ΔE (a*, b*)>3.24 and ΔE (L, a*, b*)>3.57 with respect to the nominal color of the ISO DIS 8654:2017 5N alloy.
4 more elements
A Gold alloy for jewelry, consisting of, in weight:
- Gold, in the amount comprised between 755‰ and 770‰,
- Copper, in the amount comprised between 170‰ and 180‰,
- Silver, in the amount comprised between 38‰ and 42‰,
- Palladium, in the amount comprised between 19‰ and 23‰ and
- Iron, in the amount comprised between 4.5‰ and 6‰.
2 more elements
Dependencies are inferred from the claim text.