The Physics and Optical Properties of Gold

Abstract

Although gold is well down on the periodic table, at position 79, it was the first of the metals to be discovered and exploited by humans. This was almost certainly as a result of it possessing four unique attributes: a bright metallic yellow color, excellent resistance to corrosion, considerable malleability, and a high density (19.32 g/cm3). The high corrosion resistance and density facilitated the concentration of native gold nuggets and powders in the beds of streams, while the yellow color and malleability made it very suitable for the production of jewelry or religious artifacts. A few other metallic elements-such as silver, copper, or platinum-possess color and/or corrosion resistance and/or ductility and/or density, but none to the simultaneous degree exhibited by gold. What are the reasons for this unusual cluster of interesting properties in element 79?