A Guide to Lab Grown Diamonds
When it comes to social issues like sustainability and human rights, the world is changing before our very eyes, and the diamond industry is no different. We are seeing the diamond industry change drastically. These changes are being brought about due to many different issues surrounding responsible diamond mining. The foremost recent event having the largest impact currently is the war in Ukraine and the sanctions placed on Russia from the west…specifically the halting of import from the diamond mine, Alrosa, from which 30-40% of all of the world’s diamonds come. Inflation has definitely impacted the diamond trade pricing lists across the world. And finally, with the looming inevitability of open pit diamond mines closing around the word, rough natural diamond sourcing and production is more limited than ever. In 2020, the Argyle mine in western Australia closed its operations after 37 years - stating the yield didn’t outweigh the costs. To place this into perspective, at one point the Argyle mine was responsible for 40% of the world’s gemstone production, read more HERE. With these constraints on naturally mined diamonds across the world we have seen a major increase in natural diamond prices (both polished and rough) over the past year. Not only have we seen the price increase we’ve also felt the squeeze of having less inventory on the market.
How is the diamond industry responding to these issues? In the United States - and in much of the world - a diamond engagement ring is still seen as a part of the marriage proposal process. Therefore, diamonds and other simulants are still in demand. Since this demand is still alive and thriving and natural diamonds have experienced such drastic changes, what other gemstone is suitable for an engagement ring that will last the test of time? There are many diamond simulants out in the market right now. Some diamond simulants include: Synthetic Moissanite, Colorless Sapphire, and Cubic Zirconia. The issue with these simulants is that they are not as hard as natural diamonds on the “Mohs Hardness Scale” (which measures a gemstone’s hardness - a diamond is 10 out of 10). These gemstones, though bright and beautiful, will chip, fracture, and break under high pressure. So, you may ask: “Have laboratories and companies found a way to recreate the diamond creation process in a laboratory?” The short answer is yes, we now have the technology to create a laboratory grown diamond.
Laboratory Grown Diamonds (LGD)
A lab grown diamond has the same chemical composition (Carbon, C) as a natural diamond which came from the earth, except this type of diamond can be grown in a facility with some pretty amazing machines using energy. (Just how much energy does a lab grown diamond produce? Read Jewelers magazine JCK HERE to find out). In 1954, General Electric started synthesizing the first laboratory grown diamond through High Pressure and High Temperature (HPHT). They weren’t able to grow a large lab grown diamond by any means, however, they did open the door for HPHT process to flourish. Lab grown diamonds can be produced in one of two ways. Either High Pressure High Temperature (HPHT) or through Chemical Vapor Deposition (CVD). (Are you looking to learn more about how the lab growing diamond process works? Click HERE to a link to The Gemological Institute of America, GIA.) In recent news, this past February 2022 the largest lab grown diamond was produced by the Chemical Vapor Deposition CVD process at 16.41 carats (Click HERE to read more from National Jeweler).
Chemical Vapor Deposition (CVD)
In short, How is a CVD lab grown diamond made? According to Dr. Robert Linares, owner of the consulting firm Integrated Diamond Technologies, LLC. in an article that can be read HERE : “The CVD process is quite different from natural diamond formation. It produces a diamond from a heated mixture of a hydrocarbon gas (typically methane) and hydrogen in a vacuum chamber at very low pressures.” Dr. Linares goes on to say “to produce a gem-quality synthetic diamond, a diamond seed crystal (natural, HPHT, or CVD in origin) is introduced into the gas mixture, at an elevated temperature of 900 to 1200°C. The activated carbon-hydrogen species travels across the surface of the diamond seed until it finds an available carbon atom, and then attaches itself to this seed atom. The seeded growth is now one carbon atom thicker. This process repeats itself endlessly to replicate the crystal structure of the diamond seed crystal in three dimensions.”
High Pressure High Temperature (HPHT)
In contrast, how is an HPHT diamond made? According to Dr. Sigley, a distinguished research fellow at GIA in Carlsbad in an article read HERE : “A Diamond seed is placed in a specifically designed press. The growth chamber is heated to 1300-1600 °C with pressures above 870,000 pounds per square inch. The molten metal dissolves the high purity carbon source. Carbon atoms precipitate on a small diamond seed crystal, and a synthetic diamond begins to grow.”
Recent Experience
I was recently working with a client who dove head first into the lab grown diamond industry. I had the opportunity to work with this person, and I must admit I learned SO much! I always say that knowledge is power. The more you know the better it will be for you when it comes to purchasing. This particular client was looking for a lab grown diamond with the following characteristics: Certified by The Gemological Institute Of America (G.I.A.) Oval brilliant cut diamond, 2.00ct. plus which was colorless, and flawless through VVS2 in clarity. Other special characteristics included; No Fluorescence, Excellent Polish and Symmetry, specific table and depth percentages as well as length to width ratio’s, with no clarity characteristics under the table.
As you can see, on certification paper this diamond sounds amazing. Here’s what I learned throughout the process though. This client was looking for a lab grown diamond that did not have any additional treatment or intervention past the HPHT or CVD process. This begs the question; Are lab grown diamonds treated for color and clarity enhancements? The answer is yes! One would think that the lab grown diamond is already growing under such strict growing conditions in order to produce the exact specifications designed by the manufacturers. However, after delving more deeply into the lab grown diamond industry for this specific client, I’ve learned that most of lab grown diamonds are treated a second time in some way or another. This detail can be seen in the additional characteristics listed on the certificate. Only in a small percentage of lab grown diamonds made through the HPHT process list no detection of additional treatments. I must say that this may change as technology grows, but for now, additional color and clarity enhancement treatment appears to be the norm in the production of lab grown diamonds.
Lab Grown Diamond choice
You may ask “what should I be looking for in a lab grown diamond?” Ultimately, lab grown diamonds are produced at high rates in a labs - and the prices reflect this higher supply at roughly 70-80% less per carat and are trending downwards than their natural diamond counterparts. That being said, you could argue that you would want all the highest characteristics in the lab grown stone you plan to purchase. However, based on my own experience and hundreds of lab grown diamonds I have researched, I may have some more specific advice on what to look for beyond “highest quality.” A good first question to ask is “what color lab grown diamond is best?” I have found, especially when comparing to the color of a natural stone, many lab grown diamonds have a tendency to display a grayish overtone. This phenomenon is most noticeable in the color range of D,E, and F. I would describe it as having the effect of making the gemstone look somewhat metallic. So, I would suggest lower colors such as; H, I, and J color to maintain the overall visual appearance of a natural diamond. This grayish tone wont have an impact on the official body color you will see listed on the certificate, but rather it is based on my own observations and my own opinion as a gemologist with years of experience comparing both natural and lab grown diamonds.
How about clarity? What clarity should you look for in a lab grown diamond? Ultimately if the budget allows for it, go as high as possible. Flawless, VVS, and VS1 are the highest range of clarity available, and with the much lower price range for a lab grown diamond, these specifications can often fit into the budget of many customers.
Another question you may have deals with certification: are lab grown diamonds certified? In 2007, G.I.A. started grading lab grown diamonds, and as of July 2019, G.I.A. has been providing official LGDR reports. Which grading laboratory should you choose for a lab grown diamond? As I’m sure you already know - because you’ve read so many of my blogs - I will always recommend G.I.A. as the lab grown certification of choice.
Finally, which process is best for lab grown diamonds, HPHT or CVD? Based on my most recent experience, I’m leaning towards HPHT due to less post intervention and a very similar process to that of a natural diamond’s creation. As always if you are looking for a lab grown diamond reach out to me! I have many lab grown diamond connections in the industry and can offer some pretty amazing prices!
Additional Comments
Over the years as lab grown diamonds have become more popular, there has been a misconception from the general public when it comes to the testing of lab grown diamonds. A very common question I have come across is: “Can a gemologist or jeweler tell the difference between a lab grown diamond and a natural diamond?” I can tell you this much; my office and almost every Jewelry store, pawn shop, and diamond dealer has the capability to test whether a diamond is natural or lab grown. The technology professionals use is not a normal diamond tester - where a machine tests for thermal conductivity. The diamond tester was initially invented as a moissanite tester, because a moissanite gemstone has similar thermal conductivity. At the time moissanites were considered a natural diamond alternative. And now the lab grown diamonds are seen as a natural diamond alternative. There have been developments in testing technology and now professions have at their disposal machines such as G.I.A.’s new iD100 seen HERE and Yehuda’s Sherlock Holmes 3.0 seen HERE . Using these tools, we can now immediately tell the difference between lab grown and natural. Now you may ask; Well, can you visually see with your naked eye the difference in a lab grow diamond and a natural diamond? This one is a little harder because as a gemologist I’ve been taught to never identify any gemstone on sight alone. To the average customer, however, a lab grown diamond will look very similar to a natural diamond, you could even add synthetic Moissanite to similar colorless gemstones. One thing to keep in mind, as I previously mentioned above, lab grown diamonds have a tendency to appear grayish with almost a metallic appearance. This appearance typically isn’t seen in a natural diamond. I would also add that all lab grown diamond manufacturers laser engrave their diamonds as good practice. These laser inscriptions identify each specific stone and alert the industry to the fact that they are, in fact, produced in a lab and not naturally mined. For more information on lab grown diamonds, check out this link through G.I.A. HERE.
A Take On Lab Grown Diamonds
I know and understand that every gemstone has its place in our world. I also know that due to the circumstances I’ve went into above that our world as a whole has some major issues when it comes to natural diamonds. As gemologist who has studied rare gemstones, it is hard for me to ultimately say that a natural diamond is the same as a lab grown diamond. While the chemical composition shows that they are both made of carbon, realistically, natural diamonds are extremely rare. They rise to our earth’s surface through millions of years of natural HPHT, traveling through all of the earth’s layers; lower mantle, upper mantle, then to our crust. They then need to be mined through an open pit mining operation which is very intensive. Even then - the gem quality rough natural diamond yield is roughly only 5% of the mines production! A lab grown diamond is made in a laboratory under regulated conditions over the course of about a month, and sometimes even weeks.
Now I must acknowledge that it is absolutely amazing that mankind has developed the technology to synthesize a diamond. It’s truly inspiring to see how far we have come as a society in terms of diamond production technology. One thing I urge my clients to keep in mind when comparing lab grown to natural diamonds is this: as lab technology becomes more advanced, the supply of lab grown diamonds will only increase. My prediction, and that of many other professionals in my industry, is that the price of these lab grown diamonds is only going to get more and more competitive, while the price of natural diamonds is only going to rise due to the shortage of supply I addressed in the beginning of this blog. So, what does this mean to a customer looking into buying a gemstone for a piece of jewelry? To put it simply: if you go with a lab grown diamond, you will save lots of money and come away with a stunning piece of jewelry that will hold up to the test of time - but the resale value, as you can expect, will be very low if none existant. In other words, a lab grown diamond should not be viewed as an “investment.” While you will no doubt spend much more on a natural stone, the value of your purchase will hold up due to its rarity. I also must add that this is just my personal take on lab grown diamonds. I will never decline a client searching for a lab grown diamond. I will always aim to educate my clients and guide them to the best fit for them to achieve their fine jewelry goals.
If you are looking for a lab grown diamond, I would absolutely love to help you in your search! Because of my experience and connections in the industry, I’m able to work with major suppliers of lab grown diamonds. Thank you for taking the time to read this blog. I look forward to working with you for any and all of your lab grown diamond needs.
All the best,
David F. Homsy
The Gemological Institute of America (G.I.A.)
Graduate Gemologist
