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:
“But we still remember ... above all, the cool, free aspect of the wild apple trees, generously proffering their fruit to us, though still green and crude,—the hard, round, glossy fruit, which, if not ripe, still was not poison, but New English too, brought hither, its ancestors, by ours once. These gentler trees imparted a half-civilized and twilight aspect to the otherwise barbarian land.”
—Henry David Thoreau (1817–1862)
“1st Murderer. Where’s thy conscience now?...
2nd Murderer. I’ll not meddle with it. It makes a man a coward.... It fills a man full of obstacles. It made me once restore a purse of gold that by chance I found. It beggars any man that keeps it. It is turned out of towns and cities for a dangerous thing, and every man that means to live well endeavors to trust to himself and live without it.”
—William Shakespeare (1564–1616)