Gold is a pure state is too soft for use in jewelry. Because of gold's softness and malleable tenacity, it is mixed or alloyed with other metals to make it strong and keep it from bending too readily. The minimum legal standard of karatage in the U.S. is 10K. Anything less than 10K can not be called gold. In the U.S., gold articles do not have to carry a karat or other quality mark. An alloy, or mixture of metals, is not only to produce optimum strength, but also color.
Various metals are mixed with gold to produce stronger jewelry and different colors.
White gold is often plated with rhodium, a sister metal to platinum, to give it a whiter finish. Gold Jewelry Techniques Hand fabrication is used when detailed designs make it impossible to mass produce the piece. Gold shot, or gold metal grains of any karatage, is used to create gold in sheets or wire that is pulled through a draw plate. The design is pierced or cut into the shape, bent and hammered, and finally soldered with karatage melt. Filing, sanding, and polishing complete the process.