Most of us think of gold as being a color and we associate that color with the metal we call Gold. For the most part, that is correct. What we don’t often think about is the fact that gold in jewelry can be many number of colors.
I’m not talking about Pure Gold known as 24 Karat Gold, I’m talking about the gold most of us see in jewelry. As we learned last month, most gold jewelry is an alloy or mixture of gold and other metals. Lets take 18 karat gold for example.
18 karat gold is made up of 75% pure gold. The other 25% is a mixture of other metals that give the gold its strength and its color.
Many colors of gold have been developed by combining various metals in various proportions to make up the other metals in karat gold. Some of these combinations of metals have yielded some pretty interesting and quite unusual colors.
Though not very popular, Some of these various colors of gold have become standardized. The reason for creating standards or set formulas for some of the colors of gold, is to be able to match or recreate a piece of jewelry in the exact same color.
For the most part, all these gold alloys are subtle in nature. They are all what we would consider primarily gold in color but they have a hue that is definitely pulling towards a different color. This is most noticeable when different colors of gold are seen side by side. A popular occurrence of this is found in what is commonly known as Black Hills Gold where we usually see 2 or 3 colors of gold in a single piece of jewelry.
The following is a sampling of some colors of gold and their composition. I start the list with a key to the symbols used to identify the various metals.
Symbol = Metal
Au = Gold
Ag = Silver
Al = Aluminum
Cu = Copper
Cd = Cadmium
Fe = Iron
Ni = Nickel
Pd = Palladium
Pt = Platinum
Zn = Zinc
Yellow Gold, 22 Karat
Au 91.67% – Ag 5% – Cu 2% – Zn 1.33%
Yellow Gold, 18 Karat
Au 75% – Ag 10% – Cu 10% – Zn 5%
Red Gold, 18 Karat
Au 75% – Cu 25%
Rose Gold, 18 Karat
Au 75% – Cu 22.25% – Ag 2.75%
Pink Gold, 18 Karat
Au 75% – Cu 20% – Ag 5%
Green Gold, 18 Karat
Au 75% – Ag 20% – Cu 5%
Light Green, 18 Karat
Au 75% – Cu 23% – Cd 2%
Deep Green Gold, 18 Karat
Au 75% – Cu 6% – Ag 15% – Cd 4%
Blue Gold, 18 Karat
Au 75% – Fe 25%
Purple Gold, 18 Karat
Au 80% – Al 20%
White Gold, 14 Karat
Au 58.33% – Ni 15% – Cu 10% – Zn 16.67%
White Gold, 14 Karat
Au 58.33% – Pd 14% – Zn 11% – Ag 16.67%
White Gold, 18 Karat
Au 75% – Pt or Pd 25%
White Gold, 18 Karat (No. 2)
Au 75% – Pd 10% – Ni 10% – Zn 5%
Gray White Gold, 18 Karat
Au 75% – Cu 8% – Fe 17%
Yellow Gold, 14 Karat
Au 58.33% – Cu 31.2% – Ag 4% – Zn 6.47%
Yellow Gold, 12 Karat
Au 50% – Cu 34% – Ag 16%
Green Gold, 12 Karat
Au 50% – Cu 6% – Ag 44%
Dark Green Gold, 12 Karat
Au 50% – Cu 10% – Ag 40%
Red Gold, 12 Karat
Au 50% – Cu 50%
There are many other formulas for making gold in different colors, These are just some of them.
Another method used in coloring gold takes place when gold is plated on the surface of other base metals. This plating process yields a very thin coat of gold and the color is determined by the solution and type of electrode used in the process.
Until next time,
Isidro
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~ The Colors of Gold ~ by Isidro Nilsson ~ energyrings.com