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Artificial diamonds - now available in extra large


#1

by Catherine Brahic
newscientist.com

Diamonds are a girl’s best friend, they say - and soon they could be
every girl’s best friend.

A team in the US has brought the world one step closer to cheap,
mass-produced, perfect diamonds. The improvement also means there is
no theoretical limit on the size of diamonds that can be grown in
the lab.

A team led by Russell Hemley, of the Carnegie Institute of
Washington, makes diamonds by chemical vapour deposition (CVD),
where carbon atoms in a gas are deposited on a surface to produce
diamond crystals.

The CVD process produces rapid diamond growth, but impurities from
the gas are absorbed and the diamonds take on a brownish tint.

These defects can be purged by a costly high-pressure,
high-temperature treatment called annealing. However, only
relatively small diamonds can be produced this way: the largest so
far being a 34-carat yellow diamond about 1 centimetre wide.
Microwaved gems

Now Hemley and his team have got around the size limit by using
microwaves to “cook” their diamonds in a hydrogen plasma at 2200 C
but at low pressure. Diamond size is now limited only by the size of
the microwave chamber used.

“The most exciting aspect of this new annealing process is the
unlimited size of the crystals that can be treated. The breakthrough
will allow us to push to kilocarat diamonds of high optical
quality,” says Hemley’s Carnegie Institute colleague Ho-kwang Mao.

“The microwave unit is also significantly less expensive than a
large high-pressure apparatus,” adds Yufei Meng, who also
participated in the experiments.

The new technique is so efficient that the synthetic diamonds
contain fewer impurities than those found in nature, says Meng. “We
once sent one of our lab-grown diamonds for jewellery
identification, it wasn’t told apart from natural ones,” she says.

One immediate application will be to make ultra-high quality windows
that are optically transparent to lasers. Threat to commerce

The team’s method “could be routinely run in any laboratory where it
is needed,” says Alexandre Zaitsev, a physicist at the City
University of New York, whose work also includes diamonds. “When
considered in combination with the high-growth-rate technique of CVD
diamonds, it seems to be a starting point of mass-scale production
of perfect diamond material at a low price.”

Zaitsev considers low-pressure annealing at temperatures greater
than 2000 C to be a “breakthrough in diamond research and
technology”.

The improving quality of synthetic diamonds threatens the natural
diamond market. While 20 tonnes of natural diamonds are mined
annually, some 600 tonnes of synthetic diamonds are produced each
year for industrial use alone.

They are used in a range of high-end technologies, such as lasers and
high-pressure anvils. Some companies have also started to sell
synthetic diamonds as In response, diamond giant De Beers
has set up a “Gem Defensive Programme” with the aim of finding ways
to tell apart synthetic and natural diamonds.


#2

Oh my goodness where do all of these foolish articles come from?
Mostly, it seems, from the synthetic diamond manufacturers. Yes
synthetic diamonds are available. Almost entirely they are colored
diamonds and not white ones. The claims the manufacturers make are
all overblown. There was just an article in Gems and Gemology which
describes how to identify these stones (admittedly some of requires
lab equipment most won’t have, but they have now identified things
visible under a microscope that are at least suspicious markers). De
Beers developed equipment long ago. Nothing new there. No they will
not replace natural ones (any more than synthetic sapphires replaced
natural ones).

Daniel R. Spirer, G.G.
Daniel R. Spirer Jewelers, LLC
www.spirerjewelers.com


#3

If someone looking for a really large diamond, I can point in the
right direction.

Read this article

http://tinyurl.com/62zvc6

Leonid Surpin
www.studioarete.com


#4
Oh my goodness where do all of these foolish articles come from?
Mostly, it seems, from the synthetic diamond manufacturers. Yes
synthetic diamonds are available. Almost entirely they are colored
diamonds and not white ones. The claims the manufacturers make are
all overblown. There was just an article in Gems and Gemology which
describes how to identify these stones (admittedly some of requires
lab equipment most won't have, but they have now identified things
visible under a microscope that are at least suspicious markers).
De Beers developed equipment long ago. Nothing new there. No they
will not replace natural ones (any more than synthetic sapphires
replaced natural ones). 

Well, not exactly.

CVD to grow single crystal diamonds is definitely new. And as it
says in the article CVD has a lot of advantages (low pressure, lower
temperatures, the ability to produce much larger pieces and several
others – including cost). This is very different from the high
pressure, high temperature process used to produce synthetic gem
diamonds today.

Norton and other companies have been producing CVD diamond films for
more than a decade. I remember handling an 8" disk of clear
(polycrystaline) diamond about 1/16" thick at the SEMIcon West trade
show at the Norton booth about a decade ago. For that matter, modern
hard disks have the platters coated with diamond (or diamond-like)
films grown by CVD.

The possibility of gem quality crystals is obviously what attracts
lay attention, but the first uses will undoubtedly be industrial. If
the process proves out we can expect to see a lot more CVD diamond
crystals in use.

RC


#5
Norton and other companies have been producing CVD diamond films
for more than a decade. 

Well, that’s kind of my point. Ten years ago they started producing
this stuff and there is none in the jewelry marketplace today. The
hype is almost always overblown. If you read the articles about the
other synthetic diamond producers they all make wild claims about
production ability and availability and it never seems to happen.

Daniel R. Spirer, G.G.
Daniel R. Spirer Jewelers, LLC
www.spirerjewelers.com


#6

Hi Daniel:

Ten years ago they started producing this stuff and there is none
in the jewelry marketplace today. The hype is almost always
overblown. If you read the articles about the other synthetic
diamond producers they all make wild claims about production
ability and availability and it never seems to happen. 

Yeah, but as I recall, DeBeers started flushing the vaults about 10
years ago. That should tell you their opinion of the long-term
prospects of artificial diamonds.

Regards,
Brian.


#7

The difference is what Norton and the others have been producing are
polycrystaline diamond films, not single crystals.

These researchers are claiming they can grow monocrystalline
diamonds by CVD. Those have – theoretically – potential as gems.
The Films don’t.

I don’t think gems will be the major uses for monocrystalline
diamonds, but the potential is there if it pans out.

The producers who have been doing the hyping are trying to make
That is not CVD diamond producers. If anything they’re
flying mostly under the radar.

So yes, it is in fact news that has potential implications for
jewelry.

RC


#8

maybe its the people writing the articles that are making the wild
claims about man made diamonds. i was trying to get with the people
from apollo diamond to design jewelry for them for free to help them
sell thier stuff. no real response, i am left to only speculate that
they have no money or they are being paid to lock thier doors or they
dont need business or perhaps somthing else who knows but if all this
stuff is true i wish some of us could have access to some of the
right people


#9

i sent an email to russ hemly from the article featured in the
science mag. he forwarded the message and i did recieve a response
from someone in the uk thanking me for my intrest. big industry must
not see the economic potential from thier stuff being made into
jewelry, but all of us that want this stuff need to start asking for
it a little more often perhaps engage the producers in conversation
let them get to know us as artists and crafts people and let them see
what benefits we actully have to offer society because of thier hard
work at developing this relativley new technology of cvd.

goo


#10
Well, that's kind of my point. Ten years ago they started
producing this stuff and there is none in the jewelry marketplace
today. 

CVD process was developed not to produce crystals, but wafers to
replace silicon for chip design. Jewellery application is by-product.
By itself jewellery demand is not enough to justify the expense to
develop the process.

Leonid Surpin
www.studioarete.com


#11
Yeah, but as I recall, DeBeers started flushing the vaults about
10 years ago. That should tell you their opinion of the long-term
prospects of artificial diamonds. 

Relating these two facts is a complete misunderstanding of the
diamond business and trade. DeBeers started "flushing their vaults"
for a variety of reasons, none of which had anything to do with
synthetic diamonds. The primary one was that they wanted to be able
to operate in the United States and as long as they were a monopoly
they couldn’t. Without changing their long term strategic planning
they couldn’t stop being a monopoly. They also read the writing on
the walls (after their dealings with places like the Argyle mine and
the Russians) and realized they couldn’t afford to continue acting as
the world’s steward of diamonds (i.e. the world’s price supporter of
diamonds) if all diamond producers weren’t going to work with them
and it was pretty apparent that they weren’t.

Frankly, if DeBeers thought synthetic diamonds were a viable entity
I’m pretty certain they would have entered the market for them, as
they are one of the most forward thinking companies in the world. As
it stands now, no one is producing white synthetic diamonds of any
size that are actually for sale. Additionally the synthetic colored
diamonds being produced, while less expensive than natural, are not
very cheap and still take quite a bit of time and energy to produce.
I suspect the current economic downturn is actually going to
negatively impact the synthetic market in a kind of backwards way.
If the synthetics aren’t significantly cheaper than the natural
counterparts than the people with much less money aren’t going to
buy them and the people with money (albeit slightly less) are always
going to want the natural product. I wouldn’t be at all surprised if
at least one of the synthetic diamond producers doesn’t fail within
the next 12 months.

Daniel R. Spirer, G.G.
Daniel R. Spirer Jewelers, LLC
www.spirerjewelers.com