Green gold alloys are made by leaving the copper out of the alloy mixture and just using gold and silver. It actually appears as a greenish-yellow rather than green. Eighteen karat green gold would therefore contain a mix of 75% gold and 25% silver (or 73% gold and 27% silver). Fired enamels adhere better to these alloys.
Green gold was known to Lydians as long ago as 860 BC under the name electrum, a naturally-occurring alloy of silver and gold.
Cadmium can be added to gold alloys in amounts of up to 4% to achieve a green color. The alloy of 75% gold, 23% copper, and 2% cadmium yields light-green 18-karat gold. The alloy of 75% gold, 15% silver, 6% copper, and 4% cadmium yields a dark-green alloy. Cadmium is, however, highly toxic.
Read more about this topic: Colored Gold
Famous quotes containing the words green and/or gold:
“Reptilian green the wrinkled throat,
Green as a bough of yew the beard;
He bent his head, and so I smote;”
—Yvor Winters (1900–1968)
“There is too much sour grapes for my taste in the present American attitude. The time to denounce the bankers was when we were all feeding off their gold plate; not now! At present they have not only my sympathy but my preference. They are the last representatives of our native industries.”
—Edith Wharton (1862–1937)