The best jewelers know that their true mastery of the trade is called into question when they have to differentiate two pieces that look exactly the same, but they aren’t, especially when the differences cannot be seen using ordinary tools.
Today, we look at how jewelers differentiate synthetic from natural, mined diamonds and if it’s possible for the lab-created diamonds to pass as authentic, mined diamonds.
So, let’s get started.
Can a jeweler tell a lab-created diamond?
Often, the lab-created and the natural diamond gemstones will look exactly the same, as long as they are of the same quality. As a result, even the most trained eyes may be unable to differentiate the diamonds.
Interestingly, jewelers that use traditional loupes and microscopes have a harder time detecting the differences between natural, mined diamonds and laboratory-grown diamonds. So, if you are shopping for diamonds and you aren’t keen about the source of the diamonds, you may end up with lab-created diamonds, and no one would be the wiser. In an article published by CNBC, it was noted that laboratories today have been more than successful in growing diamonds that match the quality of the diamonds that are mined, and the best part is that these lab-created diamonds have no ‘blood diamonds’ stigma attached to them. Also, these lab-created diamonds are only sold at a fraction of what you’d spend on the mined diamonds.
What you may not know is that even the low-cost tools that are used by most jewelers to tell fake diamonds from true, mined diamonds often fail and are unable to accurately differentiate between the mined diamonds and lab-grown CZ stones. As a result, it would be impossible for jewelers to confirm the authenticity of diamonds without using the most advanced gemological equipment and test procedures employed by the best in the game.
The kind of equipment that jewelers need to reliably and accurately determine the authenticity of the diamonds is complex and complicated, costing upwards of $10,000. This accurate detection method for diamonds is known as Photoluminescence Spectroscopy, and it calls for deep freezing of the diamonds to low temperatures up to −320°F or −196°C.
Naturally, most of the jewelers you know don’t have such equipment because of the high cost and how complex they are to use, which is why fake diamonds would pass as authentic diamonds even to the most trained of jeweler’s eyes.
To determine the authenticity of the diamonds sold today, the jewelers determine the authenticity of the pieces by looking up the diamond’s unique ID off the diamond database and using a microscope. Microscopes with laser inscriptions could be used as well.
How are the lab-created diamonds made?
There are two main processes that are used to make diamonds in the lab – CVD (Chemical Vapor Deposition) or HPHT (High Pressure/High Temperature).
HPHT involves growing diamonds in the lab by mimicking the way diamonds come to be naturally – which is through subjecting carbon atoms to extremely high pressure and temperature conditions. This process is, however, quite costly.
CVD, on the other hand, is a chemical process that involves mixing methane gas with nitrogen in a chamber containing a seed crystal. These components are then heated in the microwave to high temperatures, exciting the gas and resulting in the growth of the diamonds at higher temperatures. CVD is used often because it’s cheaper, which is also why it’s a popular option that’s now used to create the highest quality diamonds.
Can a Jeweler Tell the Difference Between Lab-Made and Mined Diamonds?
So, what’s the difference between lab-grown and the mined diamonds?
First, let’s take a look at what the lab-created diamonds are and whether they are real diamonds or not.
We’ll start by saying that physically, chemically, and even optically, the lab-grown diamonds are 100% identical to the natural, mined diamonds. In that sense, the lab-grown diamonds are real diamonds, and they have the same crystallized and beautiful structure and sparkle as the mined, natural diamonds.
The reason for the popularity of these lab-made diamonds has to do with their affordability. These diamonds are also known as lab-grown, lab-cultured, lab-created, or lab-synthetic diamonds, and these are all just some of the terms that are used to describe the diamonds that are made from the laboratory.
How then are the lab-made diamonds differentiated from the mined, natural diamonds?
As mentioned above, the first glance at any diamond, whether lab-created or mined, will not reveal anything different. However, there are two very minuscule details that you may want to look out for in these two types of diamonds.
Tiny Laser Inscription – using a magnifying glass, you can tell the lab-grown from natural mined diamonds by looking out for a very tiny laser inscription. This inscription would be on the girdle (the diamond’s widest part, which forms the outline of the stone when looking at it from the top).
In most cases, the lab-grown diamonds would be inscribed with words and numbers that identify the diamonds as lab-made. These diamonds would also feature a lab report number, also inscribed on the girdle. You could then take this number and enter it on a reputable gemological society’s website to access the report. This report tells you whether the diamond is lab-grown or mined, among other details.
If there are no inscriptions on the girdle, then you’d have to get a major gemological laboratory to run tests on the diamond to tell you if the diamond is lab-created or mined.
How about the diamond testers?
Well, since the lab-grown diamonds feature the same electrical and thermal conductivity properties as the mined/ natural diamonds, the lab-created diamonds would pass the diamond-tester exam.
Therefore, the only way to differentiate between the naturally mined and the lab-grown diamonds would be by using powerful microscopes and running extensive tests at the leading gemological laboratories.
How to Tell If a Diamond Is Natural or Lab Grown?
- Responsible Disclosure
This is the first thing you need to look out for when buying diamonds. The lab-grown diamonds come with a clear and responsibly disclosure telling you that the diamonds are man-made. Although there is the risk of lab-grown diamonds being sold as natural, mined diamonds, manufacturers of lab-grown diamonds are required to disclose that their diamonds are lab-grown using laser inscriptions.
- Type IIa Test
This is a diamond tester that tells if the diamonds are lab-grown or natural. Type IIa diamond test is the test that relates to the diamond variant relating to the purity of the carbon making up the diamond. Naturally, not more than 2% of all the diamonds are Type IIa diamonds, but all the lab-grown diamonds are Type IIa diamonds. This test is not, however, 100% conclusive.
- UV Radiation & Photoluminescence Spectroscopy
For 100% determination of the source of the diamonds, these two tests would have to be run. They are expensive tests that tell you about the actual nature and source of the diamonds. But since they are expensive and complex, these tests are run by the leading gemological institutions in the world, and they are very expensive.
Generally, these tests involve the use of machines to bombard the diamonds with different kinds of radiation followed by the analysis of the stone outputs. The lab-grown and mined natural diamonds have different troughs and spikes at specific spectroscopic and wavelength levels.
With similar chemical, physical, and optical features, lab-grown diamonds and the natural, mined diamonds are hard to tell apart.
So, unless you notice the laser inscriptions on the girdle or have the diamonds tested at the leading institutions, it would be impossible to tell these two types of diamonds apart.