Until recently, diamond was the hardest known naturally occurring material. But a new physical process applied to carbon has uncovered a substance that a group of scientists say is even harder.

Researchers at North Carolina State University say they have developed a technique for creating a substance they are calling Q-carbon, which represents a third phase, or distinct form, of carbon alongside graphite and diamond.

The discovery could have many applications, notably in the fields of medicine and industry. But Jay Narayan, the lead scientist on the study, has made one claim about the technique that is certain to turn heads.

“In 15 minutes, we can make a carat of diamonds,” Mr. Narayan said. A carat is 200 milligrams.

The process of creating Q-carbon — which involves concentrating a very short pulse of laser light onto carbon — can produce minuscule synthetic diamond “seeds,” which can yield gems.

While the amount of diamond is tiny compared with the yield of traditional industrial techniques, the process can be carried out at room temperature and air pressure, the researchers say, meaning it could be easier to reproduce on a large scale than other methods, including one that has been drawing interest in Silicon Valley known as chemical vapor deposition.

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But Mr. Narayan and his colleagues say the potential for creating synthetic gemstones pales next to possible applications of Q-carbon, which the researchers said is magnetic, fluorescent and electroconductive.

The technique used to create Q-carbon, which was pioneered over the summer, was described on Monday in the Journal of Applied Physics. A tiny laser beam is trained onto a piece of amorphous carbon for 200 nanoseconds, heating it extremely fast. The spot then cools in a process known as quenching, creating Q-carbon.

It isn’t known whether the substance exists in the natural world, but Mr. Narayan suggested it could be present in the cores of planets.

Wuyi Wang, the director of research and development at the Gemological Institute of America and an expert on diamond geochemistry, said that while he would like to confirm the findings himself, “if they are true, it will be very exciting news for the diamond research community.”

He added that the journal is “quite credible” and he “pretty much trusts what they say.”

André Anders, the editor in chief of the journal, echoed Mr. Wang’s excitement, as well as his note of caution.

“This is one of those ‘wow’ papers,” he said. “I put a sticky note on the manuscript that said ‘pay attention to this one’ before the peer review even happened. But the second thought I have, and this is the scientist in me, is that I’m always skeptical.”

Mr. Narayan described possible uses for Q-carbon in creating synthetic body parts, improving tools like deep-water drills, and producing brighter, longer lasting screens for televisions and cellphones.

Casey Boutwell, who works on commercial licensing for scientific discoveries at the university’s office of technology transfer, said he was bracing for strong interest in the technique. “We don’t know exactly how this can be best applied, and we’re excited to get the market’s input,” he said.

Neil Krishnan, the director of technology platforms at the Swedish industrial toolmaker Sandvik Hyperion, called Mr. Narayan’s discovery “extremely interesting.”

“I still think it’s at a nascent stage for us to consider it a competitive threat per se,” he said. “But it would definitely be a new technology that we’d be interested in.”