Glittering Gold Can Stay Shiny for Centuries. Scientists Say They’ve Figured Out Why the Precious Metal Is So Resistant to Tarnishing

When the metal is split, the atoms on its surface rearrange themselves into a very stable pattern that doesn’t easily react with oxygen in the air, a study suggests

Sara Hashemi | Daily Correspondent

June 4, 2026 11:26 a.m.

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When you think of pirate’s treasure, fine jewelry or gorgeous coins, what do they all have in common? Glittering gold. The precious metal has been coveted for millennia for its eternal shininess.

Now, scientists say they’ve finally figured out why the element is so resistant to tarnishing.

In a study published on May 21 in the journal Physical Review Letters, researchers report that gold’s long-lasting glimmer has to do with the arrangement of atoms on its surface. The element’s atoms will naturally organize themselves in a zigzagging pattern that protects them from reacting with oxygen, which explains why the metal can stay flawless for years. The findings could help researchers design useful chemical ingredients.

“Everyone knows that gold is difficult to oxidize,” says Santu Biswas, a study co-author and chemist at Tulane University, to Joseph Howlett at Scientific American. “The thing is, why? What is the proper reason for that?”

The air contains lots of oxygen molecules, each comprised of two oxygen atoms that are stuck together. When a metal oxidizes, it first splits those molecules. The newly separated oxygen atoms then steal some of the metal’s electrons, negatively charged particles, creating new chemical compounds that stick to the metal’s surface. For instance, rust forms when iron oxidizes. Silver and copper, meanwhile, become dark and dull. (Copper eventually turns green due to reactions with carbon dioxide and water in the air.)

Gold is different, staying shiny for centuries.

“People have generally thought gold doesn’t tarnish simply because it doesn’t interact strongly with oxygen,” says study co-author Matthew Montemore, a chemical engineer at Tulane University, in a statement. But he and Biswas suspected there was more to it.

The duo decided to investigate a process called surface reconstruction. When you break a piece of gold, the atoms on its surface will reorganize themselves in seconds, often from square-shaped lattice patterns into repeated hexagonal patterns. They do that by pulling atoms from the interior and shoving them onto the surface, creating a microscopically bumpy exterior.

Computer simulations helped the researchers analyze how oxygen interacts with these two common gold surface structures. They found that it’s easier for oxygen molecules to react with gold in the square arrangement. The process takes much more energy for the atoms in the hexagonal pattern. “It’s something like a billion to a trillion times slower oxidation once you rearrange,” Montemore tells Science News’ Emily Conover.

For the reconstructed hexagonally arranged atoms to react with oxygen, they would need to revert to the square shape, which impedes oxidation, the team found. Since the hexagonal pattern is more common, gold usually continues to gleam for a long time.

The researchers hope their findings could be used to design better catalysts, substances that speed up chemical reactions, which is important for chemical manufacturing and other applications. While gold is used as a catalyst in some cases, its resistance to oxidation has narrowed its usefulness.

“The exciting takeaway is that gold’s catalytic behavior may be tuned by controlling surface reconstruction,” says Hongliang Xin, a chemical engineer at Virginia Tech, who was not involved in the study, to Karmela Padavic-Callaghan at New Scientist.

For example, “you can prevent reconstruction by putting some absorbent on top of the surface,” Biswas tells Scientific American. “And then the gold can easily oxidize.”

Sara Hashemi | Read More

Sara Hashemi is a science writer and fact-checker currently based in New York City. Her work has appeared in Sierra, The Body, Maisonneuve magazine and more.