14-karat gold alloy compositions having enhanced yellow color, reversible hardness, and fine grain structure
US6676776B1 · kind B1 · utility
1Cited by
6References
16Claims
0Family size
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Key dates
| Filing date | Aug 20, 2002 |
| Grant date | Jan 13, 2004 |
| Priority date | — |
| Expiry date | Aug 20, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C5/02
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A 14-karat gold alloy composition having a desirable yellow color and with reversible hardness contains about 58.65 weight percent gold, about 11.5-25.0 weight percent silver, about 11.85-23.35 weight percent copper, and about 2-7 weight percent zinc. The color of the composition has a value of between about −3.0 to about 0.5 CieLab a* color units, and has a value of between about +20.0 to about 22.0 CieLab b* color units. The alloy has a hardness ratio between about 0.4-2.0, and color ratio of less than about 1.0.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.