In karated gold, there is a known proportion of metals in the non-gold percentage. These metals provide the various colors and hardness of karated golds. Typical alloying elements and their color effect are:
- Copper Reddening
- Silver Greening
- Zinc Bleaching
- Nickel Whitening
- Palladium Whitening
Examples of the compositions of different colors are:
- Yellow: Gold, copper, silver, zinc
- White: Gold, copper, nickel (or palladium), zinc
- Red: Gold, copper
- Green: Gold, silver
Adjusting the proportions of base metals (non-precious metals) provides the array of colors on the market. They also enhance properties such as castability, grain size, hardness, corrosion resistance, workability, ultimate strength, and ductility. These additions can dramatically change the properties of the karated gold for better or worse.
Knowing how the additions will affect the karated gold greatly enhances the possibility of a superior final product. In deep drawing of metals, it is important to have a metal which will elongate or stretch a great deal before fracturing, thus high ductility. The requirement for an earring post would be a high tensile strength (a great deal of force needed to get the material to permanently deform, bend). It is imperative to select the proper karated composition for the desired application.