Every jeweler and metalsmith should understand the difference between a "gold alloy" (sometimes called a pre-mixed gold alloy or karated gold) and a "master alloy." A gold alloy must contain gold in the amount specified. A master alloy is a blend of non-precious metals intended to be mixed with gold.
A gold alloy has a specific amount of gold combined with other elements, such as copper, silver, nickel and zinc. The metals added to gold are called “alloying additions.”
The most convenient way to add alloying additions to pure gold (to create a lesser karat value) is to pre-mix the alloying metals into a master alloy that will give the gold alloy specific physical properties such as color, strength and density.
When you buy a master alloy, you receive a combination of metals that must first be mixed with pure gold to create your gold casting alloy. All gold casting alloys start with pure 24K gold, which is a brilliant yellow and very soft. The master alloy you choose determines how color and other characteristics change in the final gold alloy. A master alloy labeled “14K rich yellow” will produce a rich yellow 14K gold alloy when it is properly mixed with 24K gold.
It is quite possible to raise the karat value of gold that has already been alloyed; however, care must be taken to avoid mixing dissimilar master alloys. Mixing master alloys made with different metals usually results in the loss of the intended properties of either master alloy.
Using master alloys gives you the advantage of having a wide range of colors on hand at a low cost compared to stocking several amounts of karat gold. Rio Grande offers a complete range of master alloys you can use to create many colors and karat values of gold--including nickel white and nickel-free palladium white.
If you make your own sheet and wire, you can customize your casting alloys to produce the best working properties for your particular needs. This means less cracking as you roll or pull your own metal to your required sizes.
If you create your own alloys, (or when you’re ready to begin alloying your own metals) depend on Rio to be your partner in success!