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A Rainbow of Options

Gold offers a rainbow of options – who knew? The many color options occur when you alloy gold with other elements in varied proportions. There is a gold choice for every skin tone, color palate, and taste or style. Yellow, white, rose or pink, green, grey, black, blue and purple! The natural color of gold is the yellow form, and as we learned before, white gold is created by adding silver, nickel, manganese or palladium into the gold composition. Rose gold, otherwise known as pink or red gold, uses copper as the alloy to produce the red hue. The color tone in the name will depend on the strength of the coloration. Green gold alloys are made by leaving the copper out of the alloy mixture and just using silver and natural gold. Black gold is made using several different methods. It can be electroplated, using a black rhodium or ruthenium. Another method is a process called Patination, which is applying sulfur and oxygen containing compounds. Another process commonly used is plasma assisted chemical vapor deposition that involves a shapeless carbon. Most recently, a laser technique has been developed that renders the surface of metals a deep black. A laser pulse deforms the surface of the metal forming nanostructures. The greatly increased surface area can take in virtually all the light that falls on it, making it black. Grey gold alloys are made by adding silver, manganese and copper in specific ratios to the gold. Lastly, the least common colors, purple and blue gold. Purple, also known as amethyst or violet gold, is an alloy of gold and aluminum rich gold-aluminum intermetallic. It took many years to find the correct combinations to make it malleable enough to withstand shaping and also less reactive to contaminants. Blue gold is the least common coloration, as it’s hard to have in the composition that is not too brittle to be enjoyed in jewelry form. It is an alloy of gold and indium, or gallium. To make it less brittle sometimes a small amount of palladium, copper or silver will be added to the compound.