PINK COLORED METAL ALLOY HAVING LOW GOLD CONTENT
Pink colored metal alloys have a low gold content. The pink colored metal alloys of the present disclosure display a high level of tarnish resistance during extended use and wear, and have the appearance and properties comparable 10 karat (or above) gold alloys, which have a significantly higher gold content.
1 . A pink colored metal alloy comprising, by weight percent with respect to the total weight of the alloy: about 33.0% to about 20.0% Au; about 60.0% to about 45.0% Cu;
about 14.8% to about 2.5% Ag; and 0% to about 5.0% Zn.
2 . The alloy of claim 1 , further comprising from about 0.001 to about 1% X, wherein X is one or more elements selected from the group consisting of silicon, germanium, cobalt, iridium, ruthenium, boron, and mixtures thereof.
3 . The alloy of claim 2 , wherein X is silicon and germanium.
4 . The alloy of claim 3 , wherein the weight percent of X from about 0.1% to about 0.3%.
5 . The alloy of claim 2 , wherein X is silicon.
6 . The alloy of claim 2 , wherein X is germanium.
7 . The alloy of claim 1 , wherein the weight percent of the Au is from about 32% to about 25%.
8 . The alloy of claim 1 , wherein the weight percent of the Cu is from about 56.0% to about 54.0%.
9 . The alloy of claim 1 , wherein the weight percent of the Ag is from about 12.8% to about 10.8%.
10 . The alloy of claim 1 , wherein the weight percent of the Zn is from about 0.8% to about 1.2%.
11 . A pink colored metal alloy comprising: gold, copper, zinc and silver, wherein the gold is present in an amount of from about 33.0% to about 20.0% by weight percent with respect to the total weight of the alloy; and ratios of the percentage by weight, with respect to the weight content of gold, copper, zinc and silver only, of copper:silver and copper:zinc are from about 15.0(Cu):1.0(Ag) to about 3.0(Cu):1.0(Ag) and from about 70(Cu):1.0(Zn) to about 15(Cu):1.0(Zn), respectively.
12 . The alloy of claim 11 , further comprising from about 0.001 to about 1% X by weight percent with respect to the total weight of the alloy, wherein X is one or more elements selected from the group consisting of silicon, germanium, cobalt, iridium, ruthenium, boron, and mixtures thereof.
13 . The alloy of claim 12 , wherein X is silicon and germanium.
14 . The alloy of claim 13 , wherein the weight percent of X from about 0.1% to about 0.2%.
15 . The alloy of claim 12 , wherein X is silicon.
16 . The alloy of claim 12 , wherein X is germanium.
17 . The alloy of claim 11 , wherein the weight percent of the gold is from about 32% to about 25%.
18 . The alloy of claim 11 , wherein the weight percent of the copper is from about 56.0% to about 54.0%.
19 . The alloy of claim 11 , wherein the weight percent of the silver is from about 12.8% to about 10.8%.
20 . The alloy of claim 11 , wherein the weight percent of the zinc is from about 0.8% to about 1.2%.