White gold jewelry alloy

DETAILED DESCRIPTION OF THE INVENTION This invention provides low cost white gold alloys having highly desirable physical and chemical properties including the color, hue, luster and shine characteristics found in 10 and higher karat white gold.
According to the practice of this invention, low cost substitute white gold alloys may be produced with good corrosion and tarnish resistance, good workability and good castability.
The alloy can be hammered, cast, rolled and made into wire.
Thus, the alloy is capable of being formed into a variety of sizes and shapes by techniques traditionally used in the jewelry industry to form jewelry articles of a desired size and configuration.
The alloy may also be cut and sized with solders conventionally used in the jewelry industry and can be plated with precious metals such as rhodium if desired.
The alloy is preferably in the less than one-half karat gold range, that is, up to about 2% gold and preferably 0 to 1% gold.
Thus, the alloy is relatively low cost but nevertheless has a surface appearance including color, luster, shine and hue which is substantially identical to that of 10 higher karat white gold.
The alloy contains the following constituents in weight %:
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Silver 25.
30%
Palladium
16.
80%
Nickel 9.
60%
Copper 32.
40%
Zinc 13.
40%
Platinum
1.
55%
Gold 0.
86%
99.
91%
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Various optional elements may be found in the alloy.
Platinum up to 5% may be added to improve tarnish resistance.
Tin up to 3% improves the hardness of the alloy and provides a little better color.
Gallium up to 5% provides the alloy with a slightly better color.
Aluminum may be present up to 3%; however, a high percentage of aluminum decreases the tarnish resistance of the alloy.
Iron up to 3% keeps the alloy from turning too white with age.
However, higher percentages of iron decrease the tarnish resistance of the alloy