What is the difference between lab grown and natural diamonds?

The first lab grown diamonds were formulated in 1953 by Swedish researchers, followed by American electricity giant General Electric in 1954. Initially, “synthetic diamonds” were undertaken for industrial uses like as drill bits and saw blades. Now, created diamonds are increasingly being seen by millennial and Gen Z consumers as an ethical alternative to traditional mined or dredged diamonds. While man-made and natural diamonds share the same chemical structure and visual appearance, there are nuances between the two that could be make or break qualities for diamond shoppers. Here, we drill down to the differences in formation, processing time, clarity, and valuation between earth and lab diamonds.

The two techniques for making lab grown diamonds are High Pressure High Temperature (HPHT) and Chemical Vapour Deposition (CVD). These processes imitate the environment of immense pressure and heat where diamonds form over one hundred kilometres deep inside the Earth.

HPHT was the process used to create the first lab diamond. In this system, a diamond seed (a small slither of another diamond about as thick as a human hair) is placed inside a sealed chamber which is heated to temperatures up to 1,500 degrees Celsius and pressurized. Carbon atoms are dissolved, which then bond to the seed layer by layer over a period of weeks to form a diamond rough.

In the CVD method, which was developed more recently, involves putting a seed into a chamber with carbon-rich gas like methane. This gas is ionized to separate the carbon atoms, which then fall onto the diamond substrate to build up layers. CVD results in a diamond rough that is larger than that of HPHT-formed diamonds.

Lab diamond technology has advanced to the extent that it is much faster and cheaper to culture a diamond in a machine today than it was 70 years ago, increasing competition between the traditional and lab diamond industries.

Three factors are required to form natural diamonds: carbon atoms, crushing pressure and high temperature. In certain geological zones of Earth’s mantle, the temperature-pressure conditions are ripe for diamond formation: approximately 150 kilometres below the surface, temperatures are at least 1,050 degrees Celsius. 

Carbon that is present at this depth has likely been trapped there since Earth’s formation or been delivered there by oceanic plates (the crust underneath our oceans) being pushed into the mantle by plate tectonic movement. The precious stones that eventually form can remain there for millennia until transported to the surface of the planet during volcanic eruptions.

It isn’t a straightforward process to date diamonds, since they don’t seem to grow continuously; certain conditions are required as catalysts. However, scientists agree that earth diamonds seem to form over millions of years. Most of the diamonds in the Earth’s crust likely formed between one and three billion years ago, in the early stages of the Earth’s existence.

In contrast, the HPHT method takes a few days to a few weeks to grow a one-carat diamond, while the CVD method takes up to one month to make a diamond of the same size.

There are nearly zero chemical differences between diamonds formed underground when the Earth was still young and those formed in a lab. Both, in their purest form, are made up of carbon. However, lab grown diamonds generally have less nitrogen, which gets caught in earth diamonds during their natural formation. While nitrogen can be incorporated into man-made alternatives, this process is more highly fine-tuned.

In fact, the term “synthetic” is inaccurate because lab diamonds are real diamonds. As of 2019, the Gemological Institute of America (GIA) no longer uses the term in its Laboratory-Grown Diamond Reports.

Diamonds rate a perfect 10 on the Mohs Hardness Scale, as the hardest mineral known to man. Diamonds are formed by a tetrahedral crystal structure. This results from carbon having four electrons tightly interlocking with four other carbon atoms. Curated diamonds have an identical hardness of 10, making them just as durable as mined/dredged diamonds.

Clarity in coloured gemstones is a measure of the amount of:

• Inclusions: Imperfections within the gemstone;
• Fractures or fissures;
• Surface imperfections.

Lab grown diamonds generally have excellent quality due to the highly controlled setting they form in, but they can also have inclusions that are remnants of the growth process. The common types of inclusions in lab diamonds include:

• Crystals: These look like miniature crystals and can be colourless or coloured;
• Clouds: Clusters of tiny needle-like inclusions.

Mined diamonds contain a greater variety of inclusions, especially bits of other minerals that got stuck inside the diamond as it was forming. In the gem world, inclusions are used to determine clarity grade but are also seen like birthmarks, unique identifiers that give a stone its particular look and feel.

Natural diamonds are rarer than lab diamonds due to the simple fact that the latter can be created at will. This abundance of supply makes the price of man-made stones significantly lower than natural stones, which have limited supply. But as touched upon previously, natural differences can also be present in lab diamonds, making one lab grown diamond unique from another.

Mined diamonds can be customized for cutting, setting and centre stone pairing, but you’re limited to what can be done to an already formed stone. On the other hand, lab diamonds can be customized from scratch for colour, size and shape, making them a fantastic option for eco-conscious wedding or engagement rings to maximize your budget.

The detrimental impact of diamond mining on the environment, wildlife, and humans is well-documented. While not all diamonds extracted from the Earth are “blood diamonds” or “conflict diamonds” involving human rights abuse, the effects of mineral resource exploitation include:

• Deforestation
• Surface water pollution
• Noise pollution
• Soil erosion
• Disruption of surrounding animal habitats
• Worker health hazards, e.g. respiratory illnesses from inhaling dust from open-pit mines

While the lab-grown route avoids these issues completely, it can also have its own environmental impact. Growing a diamond is energy-intensive, and how sustainable a man-made diamond is depends on the energy used to constantly run the machines making it. If a lab diamond provider uses renewable energy like that from solar or geothermal sources, the whole process is more environmentally-friendly than a lab that uses fossil fuel energy, for instance.

As discussed, natural diamonds are more expensive than mined diamonds because they’re more scarce. While the lab grown market is constantly changing year to year, lab diamonds are approximately 50-60% cheaper than earth diamonds. This also affects resale value. How this figure will change is uncertain, as demand continues to rise and supply has no limit.

It’s impossible for the average shopper to distinguish a natural from man-made diamond with the naked eye. Even traditional tools used to analyse diamonds are insufficient because the chemical makeup and physical properties of the two are identical. 

In order to identify a lab grown diamond, you need a grading report from a gemologist trained in using special techniques like spectroscopy, testing equipment, or looking through a microscope for a laser inscription sometimes used to identify lab created diamonds.

Created and natural diamonds have important differences (and similarities!) that range from rarity affecting price, to environmental and human impact, and clarity. Demand for lab grown diamonds grows as the newest, green-educated generation of precious gemstone shoppers starts to become a majority in the diamond market. Inter-Pacific creates and sources ethical created gemstones including diamonds, emeralds, and rubies for eco-friendly jewellery brands’ needs. Contact us to learn more about how your brand can benefit from a steady supply of high quality lab-grown gemstones.