Researchers at Tulane University say they have uncovered a key reason gold keeps its shine for so long. According to the study, published in Physical Review Letters and reported by ScienceDaily, the answer is not just chemistry but the way atoms arrange themselves on the metal’s surface.
The team found that atoms on certain gold surfaces naturally shift into protective patterns that make it much harder for oxygen to react with the metal. That surface rearrangement helps explain why gold jewelry, coins, and other objects can stay lustrous for centuries.
Matthew Montemore, an associate professor in chemical engineering at Tulane, said researchers had long believed gold resists tarnish mainly because it does not interact strongly with oxygen. The study, he said, shows that two common gold surface types actually reorganize themselves in ways that make oxidation even more difficult.
Using computer simulations, Montemore and co-author Santu Biswas examined how oxygen molecules behave on the surfaces of gold. Their results suggest that without the restructuring, oxygen could break apart and react with the metal much more easily.
According to the researchers, the reorganized surfaces reduce oxygen reactions by a factor of a billion to a trillion. The findings may also help scientists design better gold-based catalysts for industrial manufacturing and clean energy applications by finding ways to control or reverse those surface changes.
