Everything You Need To Know About Lab Diamonds

Lab-cultured diamonds have taken the jewellery world by storm, serving as the perfect affordable and eco-conscious alternative to natural diamond stones. So, what do you need to know?


Lab diamonds are chemically and structurally identical to natural diamonds and have the same perfect 10 on the Mohs scale. Authentic lab-created diamonds are GIA certified with a description of the diamond's 4 Cs – with only one additional entry identifying the stones as lab-grown.


As a relative newcomer to the jewellery scene – it is understandable that diamond lovers have a few unanswered questions about these manufactured gemstones. In this article, we'll give you the rundown on the basics of lab diamonds, debunking some misconceptions and answering your most popular questions.


What Are Lab-Cultured Diamonds Made Of?

Lab diamonds (otherwise known as cultivated diamonds, man-made diamonds, or synthetic diamonds) possess an identical physical and chemical makeup to natural diamonds, consisting of carbon atoms arranged in the same latticed crystal structure characteristic of earth-grown diamonds.


The only real difference is that one has been cultured in a controlled laboratory environment over a few weeks, while the other has been growing under the earth for over a billion years.


Lab diamonds are not to be confused with moissanites, cubic zirconias, or other lookalike gemstones – all of which possess different chemical structures and aesthetic traits that are visible to the naked eye.


Lab diamonds can come in various colours and clarities (including classic black diamonds and unique, vivid colourings that usually occur extremely rarely in nature) depending on the conditions under which they are cultivated. However, classic colourless and white variations remain the most popular lab diamond options, as seen below.


How Are Lab-Cultured Diamonds Made?

Most lab diamonds are made using the two processes developed to cultivate jewellery-grade diamonds: the High Pressure/High Temperature (HPHT) and Chemical Vapour Deposition (CVD) methods.


High Pressure/High Temperature (HPHT)

The key to the HPHT method is in the name – as it is predicated on imitating the same high-stress conditions deep under the earth that allow carbon to be transformed into diamond.


A small diamond "seed" is placed in pure carbon (sometimes including a mixture of hydrogen and nitrogen) within a large hydraulic press that applies around 1.5 million PSI (pounds per square inch) of pressure and is then heated to 1500°C.


Over time, the carbon melts down and forms diamond crystals around the seed – forming the base for the lab diamonds that will be cut and polished once the process is completed.


The HPHT process is a tried and true method that has been used and improved upon since the 1950s, and is the method used to produce the lab diamonds used by Southern Cross Jewels.


Chemical Vapour Deposition (CVD)

The CVD method is a little newer, introduced in the 1980s, and involves extracting the chemical elements necessary for diamond formation from carbon-rich gasses such as methane.


Similar to HPHT, a small diamond "seed" forms the base of the lab diamond – and is placed into a sealed growth chamber filled with hydrogen and carbon-rich gasses. The chamber is then heated to 1000°C, ionising the gasses into plasma.


Microwave beams extract the carbon from that plasma, depositing the extracted carbon materials onto the seed in layers, allowing the CVD diamond to form over time. Mindblowing, right?!


Are Lab Diamonds GIA Certified?

Yes! Lab diamonds have been certified by the Gemological Institute of America (GIA) since 2007.


As of 2019, GIA certifications for lab diamonds no longer include the word "synthetic" in reports, as they believe that this wording would mislead consumers into believing that lab-made diamonds are "fake" or some imitation stone – as opposed to being chemically and physically identical to the natural thing.


Instead, they use the standard reporting that describes the cut, colour, and clarity of the diamonds – with only one additional entry identifying the stones as lab-grown.


Other gemstone identification and grading laboratories worldwide have followed suit in this change – with all Southern Cross Jewels' lab diamond pieces being similarly graded in their diamond reports.


Can You Tell The Difference Between Lab-Cultured and Natural Diamonds?

Aesthetically, there is no perceptible difference between lab and natural diamonds – both possess equal reflectiveness and colour diffusion levels, giving you the same famous sparkling brilliance that diamonds are known for.


As the physical and optical properties of both gemstones are identical, any differences between the two are imperceptible without advanced laboratory tech – which can be used to detect microscopic differences in structure that may indicate how they were formed (such as the growth directions).


Recent advances in lab diamond technology have made the process even more sophisticated – resulting in cultured diamonds that cannot be told apart from earth-grown stones by regular testing means. As a result, newer lab diamonds sold on the market come with microscopic laser inscriptions on the stone's girdle – identifying them as man-made.


For this reason, it is important for anyone looking to acquire a piece of diamond jewellery to ensure that it comes with some form of certification that can be reliably traced back to its source to ensure that your diamonds are authentic, whether natural or lab-made.



 Every piece of Southern Cross Jewels’ lab diamond jewellery comes with additional certification from South Africa’s leading independent gemstone identification laboratory.


Are Lab-Cultured Diamonds As Strong As Natural Diamonds?

Lab diamonds (both HPHT and CVD) have a perfect score on the Mohs scale of 10/10, a level of hardness and durability that is only shared by natural diamonds. Thus, your lab diamond engagement ring would be just as durable as a natural one, with no additional care or cleaning instructions required.


Can Lab Diamonds Scratch?

No, just like natural diamonds, lab-made diamonds cannot be damaged by anything other than another diamond.


The first lab-made diamonds of the 1950s were almost entirely produced as industrial-grade stones for use in drill bits and diamond saws – just as natural diamonds are! It was only until the 1980s that laboratories moved away from purely focusing on the strength and durability of lab diamonds. Instead, it began producing jewellery-quality stones with more desirable colouring and clarity.


Will Lab-Grown Diamonds Get Cloudy?

Unlike diamond lookalikes such as cubic zirconias or moissanites, your lab diamond will never lose clarity over time. Just like a natural diamond, it will remain as sparkly and brilliant as the day it was brought home.


In Summary

Now that you have a solid understanding of the lab diamond basics (and congratulations for making it this far without skipping if you did!), you have learned:

  • There is no significant chemical or structural difference between lab and natural diamonds.
  • Lab diamonds, like natural diamonds, should be purchased along with accompanying certification of their origins and grades.
  • Lab diamonds have the same perfect 10 on the Mohs scale as natural diamonds and will never degrade.