This is a good article discussing Lab grown diamonds. It's a little dated, but still pretty good.
The ability to grow true gem-grade diamonds in a lab has been a long standing goal of science and industry, and one that has been achieved on a limited basis over the past five years.
Unfortunately most media publications are usually designed to sell articles, and thus often do not provide consumers with a true picture of the commercial reality and availability of lab-grown diamonds. Further, many sellers of diamond simulants (stones that look similar to diamond, but are not real diamond) exploit this knowledge gap as a way to deceptively sell their simulants as ''lab-grown diamonds''. As the president of a company that has been involved with both lab-grown diamonds and diamond simulants for over seven years, and having seen the confusion many of these less than factual articles have caused, I wanted to help provide customers with an industry insider assessment of what is and is not commercially available, and help educate those who are indeed looking to purchase a true lab-grown diamond. Thus, we begin a short tour of myth vs. reality in the lab-grown diamond market (circa 2007).
First and foremost, lab-grown diamonds (real diamond, but not mined) are in fact available for jewelry purchase, but on a limited basis. The significant catch though is this - when most people think of a diamond, they automatically think of white diamonds. As of October, 2007, no one is currently able to offer white (colorless) lab grown diamonds for sale on any type of production basis. Regardless of what various reporters write, the reality is only fancy color diamonds (predominantly yellow, and to a much lesser degree, pink and blue) are available.
The reason for that gap between what consumers want (white lab-grown diamonds) and what labs can deliver (mostly yellow lab-grown diamonds), is due to both commercial value and natural barriers. Lets discuss the natural barrier first - yellow diamonds are yellow because they incorporate nitrogen into their crystal structure. White diamonds are white (or clear) because they have much less nitrogen in their crystal structure. When growing diamonds, however, nitrogen is a catalyst - it significantly speeds up diamond growth, and in addition reduces defects. Thus, you can grow a 1ct (finished) yellow in roughly one week, versus growing the same size white (by restricting nitrogen) can take you 4-6 weeks (using BARS method, the default method currently). In other words, nitrogen can help you grow up to 6x as much yellow diamond as white in the same amount of production time. That''s a tough natural barrier.
The commercial barrier, is that yellow natural diamonds are worth much more than white natural diamonds. In nature, there are roughly 10,000 whites for every fancy yellow. Thus, fancy yellows command a much higher price per carat. Lab grown diamonds typically sell at a discount but are still pegged to their natural counterparts, and since yellow diamonds are worth more than whites, the absolute selling price for lab grown yellows is higher than what the market will pay for lab grown whites.
Now, if you combine the fact that labs can grow yellows much more quickly and easily than whites, and that yellow diamonds (lab grown and natural) further command higher prices than whites, you can see you have a severe dis-incentive to produce white diamonds with the current technology. White diamonds can and have been produced by labs (we have some sample photos on our website) but they are not price competitive with natural white diamonds at this time. Hence, a very big reason for why there are currently no white diamonds available for commercial sale.
These fundamental reasons are typically not explained in most published articles about lab grown diamonds, and many articles typically leave the reader with the exact opposite impression, that white lab grown diamonds are plentiful and cheap (remember the $5/ct quote from Wired magazine?). Various unethical simulant (CZ) makers have utilized this confusion to deceptively advertise their imitation diamonds as being "flawless man-made diamonds", "perfect lab-grown diamonds", etc. all for the low price of $100/ct. And based on emails we''ve received from customers, people have been tricked into buying plain CZ, after being told it was a ''lab grown white diamond'' and having seen articles discussing the advent of lab-grown diamonds being available.
There are two easy ways to avoid being suckered into unethical advertising like that. First of all, the price. To cut a 1ct finished diamond, you need between 2-3 carats of rough diamond to start. Cutters charge by the carat for their cutting work, and $100-$150/ct is a common rate. That means even if the diamond material were free, a seller would still have to charge at least $200-$450/ct just to break even on the cutting cost. And obviously, the lab grown material is not free and the seller would like to make a profit instead of break even, so if you see a seller selling ''cultured diamonds'' or ''man-made diamonds'' for less than several hundred dollars per carat, you can be assured it is not real lab grown diamond, regardless of what claims they make. Currently, lab-grown yellow diamonds are selling for around $4,000/ct. And remember, yellows are produced up to 6x faster than whites, so you are unlikely to see lab grown white diamonds selling for much less than that in the future unless someone figures out a much faster way to grow diamond.
The second way to protect yourself, for lab-grown diamonds of any size (i.e. .30ct and higher), is to only buy a lab-grown diamond that comes with a certificate from an independent lab. Just like natural diamonds, virtually all major gem labs now offer grading reports for lab grown diamonds (including, as of this year, the GIA). They are basically the same reports as they issue for natural diamonds, but with the origin listed as "lab-grown". If there is no certificate with a ''man-made diamond'' of any real size (i.e. .30ct or larger), and the seller declines to provide one when asked, then you can also be pretty sure its a simulant being called a lab-grown diamond.
Checking for the price and the grading certificate can ensure you are dealing with an ethical seller of lab-grown diamonds. We''ve seen many a customers whose hopes were dashed after we explained that the $150 pair of ''man-made diamond'' earrings they bought were in fact nothing more than deceptively advertised CZ. Don''t fall into that trap.
Another common myth about lab-grown diamonds is that all lab grown diamonds are ''perfect'' or flawless. As noted, the current default technology for growing diamonds (BARS method) is simply replicating the high-pressure and high-temperature present under the earth, and doing it above ground (sometimes with additional catalyst to lower the necessary temperature/pressure required). And just as diamonds from under the earth have flaws, diamonds grown above the earth also have flaws. It is a more correct analogy to think of growing diamonds (using current technology) as diamond-farming, rather than diamond manufacturing. Just like farming, you plant a seed, and try to optimize the growth conditions, but you no more get a perfect diamond than a farmer always gets a perfect tomato. In fact, sometimes after a week is up, the chamber is opened and no diamond has grown at all...so it is no where near the ''push a button, out pops a perfect diamond'' that many people think. Similarly, labs cannot customize how the diamond grows to be a specified shape (i.e. pear or emerald cut) - you get what you get, and cut to optimize the yield of each crystal.
That being said, it is true that most lab grown diamonds (especially yellow diamonds) are slightly harder than their equivalent natural diamonds. In yellows, this is due to the nitrogen being more perfectly dispersed, and Carbon-Nitrogen bonds are slightly stronger than Carbon-Carbon bonds. This is also one way labs with Raman equipment can detect man-made versus natural yellows - in yellow naturals, nitrogen is clumped, versus it is quite evenly dispersed in lab-grown yellow diamonds.
The next myth - lab grown diamonds can always be produced, so their prices will continue to drop vs. a natural diamonds will keep going up. Currently, gem grade, lab-grown diamonds are in fact substantially rarer than natural diamonds if you compare yearly production. While white diamonds are being mined in tens of millions of carats per year, lab grown whites are virtually non-existent except for research samples, and yellow lab grown diamond production is measured in thousands of carats. And because growing lab diamonds is still hard, prices for lab grown diamonds have slowly gone up, not down because there is only so much production available even as demand has increased due to public awareness.
One more reality about lab grown diamonds - size. Currently, most diamond growth chambers are unable to grow larger than 3ct piece of rough (sometimes 4ct) and thus, after cutting, most lab grown diamonds are 1.5ct or smaller (frequently smaller after accounting for flaws being cut out). The reason for this is that in order to grow a diamond using the standard HPHT (high pressure, high temperature) technology, you have to place an area under extremely high pressure and temperature. The larger the area you are trying to maintain these extreme conditions, the harder it gets..exponentially harder, in fact, because the pressure at the center is magnified due to leverage. The parts applying the pressure themselves have a limited lifespan, as they will eventually crack and fail, and require constant replacement. Thus, most labs have not tried to go beyond the 3ct size growth chamber as it does get exponentially harder to maintain the same pressure for a larger area, and that is one reason why no one is offering 6ct finished yellow diamonds for sale.
With the reality check done, we''ll end this article on a positive note - even with all the problems, costs and issues that still hamper lab-grown diamond production, colored lab-grown diamonds do offer people the ability to own and wear extremely high-end, fancy color, real diamonds at a fraction of the natural price. We''ll emphasize that these are still real diamonds - chemically, optically, physically, and of course will pass any test for being diamond (since it is diamond, the place where it was grown is the difference). Most lab grown colored diamonds are vivid in color, meaning they are among the most valuable color grades as compared to natural colored diamonds. For example, one of the first lab-grown diamonds we ever sold was graded a ''fancy vivid orangy yellow'', and was initially appraised as a natural diamond, valued at $65,000 by a major lab (we had informed them we were submitting a lab grown diamond btw). We then received a very panicked call the next day from the same lab, who after running a Raman analysis on it realized it was a man-made and not natural diamond (due to the nitrogen being so perfectly dispersed). We sold that same diamond for $3500. Similarly, most of our pink lab-grown diamonds also grade fancy vivid pink, and if they were mined instead of lab-grown, could sell for as high as $150,000/carat...we sell them for around $5,000/ct, but unfortunately due to low supply (production difficulties) are sold out most of the year. Nevertheless, the lucky few customers who do buy a lab-grown pink have a lot of fun walking into their neighborhood jewelry store and seeing the jaws drop. It is also usually the first time their jeweler has seen a real lab-grown diamond in person, again due to the relative rarity of true lab-grown diamonds. They are very beautiful and leave most natural fancy color diamonds (who are normally less intensively colored) looking pretty bland by comparison.
Technology continues to improve, and hopefully over the next few years, there will be additional breakthroughs in lab grown diamond technology. One of the most promising areas is growing diamonds by mimicking how they (theoretically) grow in outer space. This is by using ultra-low pressure, plasma and high temperature, often called plasma vapor deposition. Because it does not require the high pressure, chamber sizes are much larger and in theory, much larger pieces of diamond can be grown. Conditions are more controllable as well, due to the diamond growing by in a more nano-technology like environment (carbon-rich gas is shredded at the molecular level, and the carbon atoms then reassemble on the diamond seed below). The trade off is the machines to do this often run between $500,000-$800,000 each, and a host of additional problems not present in high pressure growth regimes come into play in this new growth environment..but hopefully in the future these will offer a new method for growing lab-grown diamonds.
Now that you are armed with industry insider knowledge, you''ll be able to readily avoid the scams that so many unethical diamond simulant sellers use by playing on the publics (and even the medias) ignorance of the realities of man-made diamonds. Hopefully, you''ll also realize that the constant claims that DeBeer''s or other forces are to blame for the lack of lab-grown white diamonds are not true (there are in fact real natural and commercial barriers to it). Finally, you''ll hopefully have an appreciation for the hard work and effort that many scientists have put into turning the former dream of lab grown diamonds into reality on your finger, even if it still has many constraints as to what types, sizes and colors of lab-grown diamonds are available.
Less P. Wright is the president of http://BetterThanDiamond.com an industry leader in white diamond simulants using lab-grown, amorphous diamond coatings, and its subsidiary, http://TakaraDiamonds.com the first to offer true lab grown diamonds to the public via the web. He is a recipient of the Gemological Institute of America''s diamond certificate.
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