Patent ID: 11889904
Assignee: ARGOR-HERAEUS SA
Field: Materials, metallurgy (Chemistry)
Classification: CPC A  C | IPC A  C

Claim 6:
7. 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.