Platinum's specific gravity is 14-19. Gold Gold is found on Earth and an equal amount is present in sea water, but very expensive to extract. It does not rust or corrode and combines beauty with easy workability, rarity, and virtual indestructibility to be a fascination to civilizations throughout time. Goldsmiths and tools were few in ancient civilizations and they worked only for the royalty and very wealthy. Today goldsmiths have machines as well as hand techniques to work the metal and make it possible for just about everyone to own and wear karat gold jewelry.
Gold is soft or can be scratched easily, and it has a malleable and ductile tenacity.
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.