Price tag enhances these gems’ appeal

Diamonds may be a girl’s best friend, but when it comes to paying for the expensive sparklers, the boy’s best friend may be Stephen D. Lux.

Lux is a chemical engineer whose company, Gemesis Corp., turns out thousands of gem-quality yellow diamonds every month from a factory in Sarasota, Fla.

Gem snobs may never go for them. But they’re not fakes -- no cheap cubic zirconias, no moissanites these. Lux is a 21st century alchemist who turns pure carbon into real diamonds, squeezing it into sturdy carbon crystals under intense heat and pressure inside his machines.

That’s how nature made diamonds, billions of years ago, deep beneath Earth’s crust. Cut and polished, natural diamonds are among the most beautiful and durable gemstones in the world. But for many would-be buyers, they also can be frighteningly expensive.

Gemesis is one of three U.S.-based manufacturers producing “cultured” or “created” diamonds. They are chemically, physically and optically identical to natural diamonds and no more synthetic than a baby conceived by in-vitro fertilization, their boosters say.

Experienced gemologists can tell the difference, but customers find them indistinguishable from the natural stones except for the price tag -- only one-half to one-tenth the price of comparable mined stones.

Three years ago, Till Somers, 64, of Scottsdale, Ariz., spent $2,500 for a 2-carat “lemonyyellow,” square-cut Gemesis diamond, set in a white-gold ring amid smaller, colorless natural diamonds.

“It really is stunning. I loved it,” she said. “If no one knows the difference, what difference does it make?”

Last month, the Gemological Institute of America, which created the industry’s international diamond grading system half a century ago, began grading machine-made diamonds much as it does natural stones.

“The GIA’s view is that material like this has a place in the jewelry trade market, as long as people know what it is, and it’s sold at an appropriate price,” said James E. Shigley, a geologist and the institute’s director of research.

Gemesis’ 4-foot-high diamond machines start with a natural diamond “seed” that is slipped inside a pressure capsule 2 feet in diameter and secured against the internal pressure with a clamping collar 4 feet wide.

The capsule is filled with a flux of pure carbon dissolved in a molten metal solvent and brought to 2,500 degrees under 850,000 pounds of pressure per square inch. The carbon at the hotter end of the chamber migrates to the cooler end and attaches itself to the seed diamond, growing the crystal atom by atom.

Each of the factory’s U.S.-made growth chambers spits out a gem-quality diamond every two to three days. The factory makes “thousands of carats per month,” Lux said, and is heading toward profitability.

The Gemesis stones are cut, polished and mounted by middlemen, then retailed in a handful of stores in the U.S. and South Africa.