Green gold
Further information: Electrum
Green gold was known to Lydians as long ago as 860 BC under the name electrum, a naturally occurring alloy of silver and gold.[3] It actually appears as greenish-yellow rather than green. Fired enamels adhere better to these alloys.
Cadmium can also be added to gold alloys but there are health concerns regarding its use.[7] 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.
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