Lab Grown vs Mined Diamonds: Can a Jeweller tell the difference?

Many traditional diamond retailers continue to push the narrative that lab grown diamonds are not real diamonds. But ask them to differentiate how they are different and you will get an uncomfortable look. Even the most experienced jewellers cannot tell the difference between lab grown and mined diamonds without expensive and specialist equipment.

So how do you find out the difference? The short answer - is you can’t without spending a lot of money. The easiest is to use a 30x magnifier to check for a lab grown diamond inscription ID. But all the rest are complicated and or expensive.

As a reminder – lab grown diamonds are real diamonds. The only difference is how they’re created. An great analogy is with ice – you can get ice from your freezer or from Antarctica – both are the same. The same is true with diamonds.

Many will have you believe that lab grown diamonds are “a second-class diamonds”. But this isn’t true. The US courts found that a lab grown diamond can be categorically termed a diamond — just like its mined counterparts. And this is because they are optically, physically and atomically the same as mined diamonds.

If you would like to learn just how diamonds are made — both mined and lab grown, you can view our article on that here.

Is It Possible for a Local Jeweller to distinguish lab grown Diamonds from Mined Diamonds?

The short answer is no. Local jewellers typically use thermal or electrical conductivity testing. These tests are used to distinguish diamonds from other gemstones. But this test doesn’t work with comparing mined diamonds and lab grown diamonds. This is because since lab grown diamonds are physically, optically and atomically exactly the same as mined diamonds.

How Can a Jeweller Tell The Difference?

1. Lab Grown Diamonds Have a Tiny Laser Inscription

Using a 30x magnifying lens you can see an ID code inscribed on a lab grown diamond. This code is used to identify, categorise and certify diamonds; and is normally located on the diamond’s girdle.

Our diamonds are graded by the International Gemological Institute (IGI) which provides a report for each diamond they grade. The report states if the diamond was created in a lab or mined and also states the properties of the diamond (e.g. cut, colour, clarity and carat size).

All our diamonds above 0.3 carats come with an independent evaluation from the IGI and a specialist jewellery insurance broker.

Without this inscription, it is incredibly difficult to know whether a diamond is lab grown or mined. All the other alternatives require high-tech and expensive equipment.

2. Checking Impurities – The Type IIa Test

This test measures the number of impurities at an atomic level. The most common elements in mind diamonds are Nitrogen and Boron. Type IIa diamonds have close to zero Nitrogen atoms in the diamond, less than 0.05%.

Type IIa diamonds are extremely rare. They only make up 1 - 2% of mined diamonds.

However, most lab grown diamonds are Type IIa. It is for this reason the Type IIa test is often used to test if a diamond is lab grown or mined. But this is not 100% reliable. Further analysis would need to be done to make sure.

3. Lab Grown Diamonds – They have Different UV Radiation and Photoluminescence Spectroscopy Results

Another method is exposing diamonds to various types of radiation. These two tests provide 100% accuracy – but are expensive. These tests are so expensive and sophisticated that they are only performed by big geological institutes (typically IGI and GIA).

After bombarding the diamond with radiation – at various spectroscopic wavelengths – you can visually tell the difference between lab grown and mined diamonds as they will show different hues.

Why? Similar to the Type IIa, mined diamonds contain impurities such as Nitrogen and sometimes Boron. UV radiation and photoluminescence spectroscopy are able to tell the difference simply because mined diamonds are less atomically perfect than lab grown diamonds!

Lab Grown diamonds: What You Should Know Before Buying

While it is extremely difficult to tell the difference between mined and lab grown diamonds it is still important that your diamond comes with certification.

Certification should come from an independent grading laboratory (e.g. IGI or GIA); and not from your retailer.

You may also think – what is stopping a lab grown diamond from being misrepresented as a mined diamond? All manufacturers are obligated to fairly represent their creation method by laser inscribing an ID on the girdle. The ID on your diamond will match the number on your certificate, allowing you to be certain that your diamond is exactly what it is reported to be on its certificate.

Gemstones that are not diamonds often do not come with certificates as there are no independent bodies that grade them. If you are buying a gemstone, it is then best to rely on an insurer’s independent evaluation of the value of your jewellery.

Conclusion

Lab grown diamonds and mined diamonds are difficult to distinguish from one another due to their comparable chemical, physical, and atomic structure.

If the jeweller can’t see the laser inscriptions on the girdle or have the diamonds analysed at expensive laboratories, it is close to impossible to identify the difference.

Our recommendation is that you only purchase an independently certified diamond, no matter who you work with when purchasing diamonds — mined or lab grown diamonds.

Choosing between lab or mined is purely a personal preference – but we truly believe that lab grown diamonds are the better option.