synthetic diamonds characteristics
Diamonds may be a girl’s best friend, but when it comes to
paying for the pricey sparklers, the boy’s best friend may be Stephen D.
Lux.
Lux is a chemical engineer whose company, the Gemesis Corp., turns out
thousands of gem-quality yellow diamonds every month from a factory in Florida,
US. Gem snobs may never go for them.
But they’re not fakes—no cheap cubic zirconias, no moissanites these.
Synthetic diamonds have a nice ring to them
Posted online: Sunday, March 04, 2007 at indianexpress.com
Lux is a 21st century alchemist who is turning
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 the
Earth’s crust. Cut and polished, natural diamonds are among the most beautiful
and durable gemstones in the world. But they can also be frighteningly
expensive.
Gemesis Corp. is one of three US-based manufacturers now 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 fertilisation.
Experienced gemologists can tell the difference, but consumers find them
indistinguishable from the natural stones, except for the price tag—only a
half to a tenth of the price of comparable mined stones.
Gemesis adds a new diamond growth chamber to its factory floor every few days
and should approach a thousand machines in the coming year, Lux said, creating
“a virtual diamond mine here in Florida.”
By way of contrast, natural diamonds formed as long as 3.3 billion years ago,
under intense pressure and temperatures more than 90 miles below the Earth’s
surface. There, atoms of carbon reorganized themselves into cubes, and the cubes
grew into crystals.
Carried back to the surface by volcanic eruptions, then exposed by erosion
and mining, they’ve been prized throughout history for their beauty and
durability.
According to the gem institute, most natural diamond crystals are “octohedrons,”
a pair of four-sided pyramids joined at the base. Most are colourless, too, but
many contain traces of other elements and impurities that lend them a variety of
“fancy” hues such as yellow, orange, pink and blue.
Although scientists first produced man-made diamonds a century ago, it was
not until 1954 that General Electric patented the first commercially viable
process. One of the first to pursue man-made, gem-quality diamonds was Carroll
Chatham of California’s Chatham Created Gems Inc., who grew the first man-made
emerald in 1938.
In 1992, with the collapse of Soviet communism, his son and heir, Thomas
Chatham, visited Russia, where he bought diamond-making technology originally
developed to serve Soviet military and aerospace needs.
Meanwhile, Gemesis founder Carter Clarke followed Chatham to Russia looking
for other business opportunities, but leaped at the chance to buy diamond-making
technology. He brought the Russian engineers and their diamond-making machines
back to Florida, where he and a scientist at the University of Florida spent the
next decade trying to perfect the machinery.
They succeeded. Today, Gemesis’ 4-ft-high, HPHT diamond machines start with
a natural diamond “seed” that’s slipped inside a pressure capsule two feet
in diameter—and secured against the internal pressure with a clamping collar
four feet wide. The capsule is filled with a “flux” of pure carbon dissolved
in a molten metal solvent, and brought to 2,500 degrees Fahrenheit under 850,000
pounds of pressure per square inch.
“It’s like growing sugar crystals in water,” explained a Gemesis
executive. 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 US-made growth chambers spits out a gem-quality
diamond every two to three days. The Gemesis stones are cut, polished and
mounted by middlemen, then retailed in a handful stores in the US and South
Africa.
—LAT-WP / Frank D. Roylance
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