CVD synthetic diamond is now gemmy and cuttable

Apollo Diamond Inc. of Boston, Mass., has successfully grown facet-sized synthetic diamonds by chemical vapor deposition (CVD).

The Gemological Institute of America (GIA) reports that four rough crystals weighing between .34 ct. and .87 ct. and four faceted diamonds weighing between .14 ct. and .31 ct. were submitted to GIA’s Gem Trade Lab for identification and research. The faceted stones were graded VS1 to SI2 (although GIA does not officially quality-grade synthetic diamonds) in comparison to natural diamonds. Colors ranged from faint to dark brown.

Typically, synthetic diamond has been grown using high pressure/high temperature presses. However, synthetic diamonds grown by CVD techniques, which do not use high pressure, has up until now produced only microscopic polycrystalline industrial quality crystals. GIA’s Gems & Gemology magazine presented a paper on the subject of CVD diamond, written by E. Fritsch et al, in 1989. Titled “A preliminary gemological study of synthetic diamond thin films,” Fritsch talks about the possible use of CVD diamond to coat other gemstones. It’s been assumed that growing single crystals large enough to be faceted would not be possible for years to come.

Apparently, that time is now.

Identification of the new CVD material is said to be fairly straightforward. GIA reports that “characteristic strain patterns were observed, which were different from those seen in natural diamonds.” Since there is no flux used in CVD processing, the usual metallic inclusions seen in HPHT synthetic diamonds will not be seen in CVD synthetics. “As a characteristic feature, the CVD synthetic diamonds displayed strong red fluorescence while exposed to high-energy UV radiation in the De Beers DiamondView.” GIA also noted that CVD diamond has “a relatively strong photoluminescence emission at 737 nm due to trace impurities of silicon.” Silicon is not found in natural diamond.

Reportedly, Apollo soon will be able to create gem-quality crystals as large as 3 cts. Both the European Gem Lab and GIA have noted that Apollo is cooperating closely with their labs. “Gemological and spectroscopic studies of additional samples will be reported in a future article,” says GIA.

But while the industry is handling this new announcement by Apollo as business as usual, the public is being introduced to the new synthetic diamonds as an industry-toppling event in WIRED magazine. In the September 2003 issue, now on newsstands with cover stating “$5 a carat, flawless, made in a lab,” contributing editor Joshua Davis (jd@joshuadavis.net) writes about HPHT gem-quality synthetic diamonds from Florida’s Gemesis Corp., and the new CVD synthetic diamond from the Boston-area Apollo Diamond company in his feature titled “The New Diamond Age.”

Leading off the article with a Hollywood hook, Davis writes: “Armed with inexpensive, mass- produced gems, two startups are launching an assault on the De Beers cartel and have the computer industry in their sights.” Adding punch to his message, Davis found an Antwerp diamond dealer who couldn’t tell the difference between a synthetic diamond, a natural diamond, and a cubic zirconia. From this, the consumer is supposed to believe that synthetic diamonds are going to ruin the diamond industry and destroy the DeBeers diamond cartel.

Of course, leave it to WIRED to report that Apollo’s “diamond wafers could be grown in large bricks,” leading the consumer to believe that entire houses are soon going to be made of synthetic diamond.

Here’s an excerpt from the article with commentary (in brackets and in bold) by JCK Gemstone Editor Gary Roskin. (Note: The article can be read online at www.WIRED.com:/wired/.)

[Davis shows a Gemesis synthetic to the diamond dealer.]

“This is very rare stone,” he says, almost to himself, in thickly accented English. “Yellow diamonds of this color are very hard to find. It is probably worth 10, maybe 15 thousand dollars.”

“I have two more exactly like it in my pocket,” I tell him.

[I think I’m starting to hear “Jaws” music in the background.]

He puts the diamond down and looks at me seriously for the first time. I place the other two stones on the table. They are all the same color and size. To find three nearly identical yellow diamonds is like flipping a coin 10,000 times and never seeing tails.

“These are cubic zirconium?” Weingarten says without much hope.

[Zirconium? Either we’re supposed to believe the editor meant to write Zirconia, which tells us that the diamond dealer can’t tell the difference between a diamond and CZ, or that the dealer really said Zirconium, which should tell us that the dealer doesn’t even know what CZ stands for!]

“No, they’re real,” I tell him. “But they were made by a machine in Florida for less than a hundred dollars.”

[Is that James Bond music in the background?]

Weingarten shifts uncomfortably in his chair and stares at the glittering gems on his dining room table. “Unless they can be detected,” he says, “these stones will bankrupt the industry.”

[Cut to commercial break! What a hook!]

Put pure carbon under enough heat and pressure—say, 2,200 degrees Fahrenheit and 50,000 atmospheres—and it will crystallize into the hardest material known. Those were the conditions that first forged diamonds deep in Earth’s mantle 3.3 billion years ago. Replicating that environment in a lab isn’t easy, but that hasn’t kept dreamers from trying. Since the mid-19th century, dozens of these modern alchemists have been injured in accidents and explosions while attempting to manufacture diamonds.”

[Yes, but please, someone make him stop!]

On the other hand, if you can get past the docu-drama of the intro, Davis actually does give the consumer their first glimpse of CVD gem-quality synthetic diamond and Gemesis HPHT synthetics. Gemesis synthetics are old news to the trade, and let’s not forget Chatham’s new line of HPHT synthetic diamonds.

With Apollo’s success, the diamond industry has yet another—and impressive—synthetic to watch for. As noted above, the new CVD diamond, like all other synthetic diamonds, are identifiable. The trade, DeBeers, and the consumer, have nothing to fear … except, perhaps, WIRED’s Davis.