The alloys of gold are expressed in carats. 24 carat gold is fine gold, which is .999 or better purity. If an alloy is mixed which is 14 parts gold and 10 parts alloy, that is 14 carat gold, 18 parts gold is 18 carat, etc. This is often expressed as the result of the ratio, ie: 14/24 equals .585 (rounded off), and 18/24 is .750. There are hundreds of possible alloys and mixtures possible, but in general the addition of silver will color gold green, and the addition of copper will color it red. A mix of around 50/50 copper and silver gives the range of yellow gold alloys the public is accustomed to seeing in the marketplace.
US Patent Issued to Korea Institute of Geoscience and Mineral Resources (KIGAM) on Sept. 18 for "Manufacturing Method of Ferromolybdenum from Molybdenite" (South Korean Inventors)
Sep 20, 2012; ALEXANDRIA, Va., Sept. 20 -- United States Patent no. 8,268,034, issued on Sept. 18, was assigned to Korea Institute of...