Gold is the most noble element ,a relatively rare element, gold is a precious metal that has been used for Jewelry, Coinage and fine arts. Because of the softness of pure (24k) gold, it is usually alloyed with base metals for use in jewelry, altering its hardness and ductility, melting point, color and other properties. Alloys with lower karat rating, typically 22k, 18k, 14k or 10k, contain higher percentages of copper, silver or palladium in the alloy.