Yet another group of researchers say they have a faster, cheaper method to manufacture large synthetic diamonds.

Researchers at the Geophysical Laboratory at the Carnegie Institution of Washington say they have can come up with a “breakthrough” variation on chemical vapor deposition (CVD), the method currently used by Boston’s Apollo Diamonds. Apollo says it is can grow large colorless stones but cannot manufacture consistently.

Dr. Russell Hemley, one of the scientists involved in the project, tells JCK his new method could eventually lead to the stones being mass-produced.

“We can make a nice 2.5 mm high gem in one day,” he says. He adds the sky may be the limit as far as size goes: “We believe that 300 carat diamonds are eventually possible with this approach.”

Still, he has no plans to market it for jewelry applications: “We are an academic group and our interest is primarily scientific and technological applications—which generally requires higher quality material than is needed for jewelry,” he says.

Last month, scientists at the University of Alabama at Birmingham announced a microwave-based technology that they said could also lead to mass-produced stones.

JCK