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Considering Lab-grown Diamonds? Here’s What You Need to Know


Growing diamonds in a laboratory sounds like science fiction, but it’s very much science fact. Lab diamonds, aka man-made diamonds or engineered diamonds, are created in laboratories using processes that mimic how diamonds are made naturally. The result is a true diamond with the same properties as a diamond that came from a mine.


Meghan Markle is known to be fond of lab-grown diamonds. In January 2019, she was spotted wearing a pair of glittering drop earrings embedded with diamonds that took just five days to grow in an Antwerp laboratory. De Beers says that the world’s natural diamond reserves are getting low, so lab-made diamonds are a sparkling solution to dwindling supplies.


Why buy lab grown diamonds?


A diamond grown in a lab comes with tangible benefits:

  • You can be certain that no mining was involved. Lab-grown diamonds are conflict-free.

  • Diamonds grown in a lab are purer than diamonds that are blasted out of rocks with dynamite. The geological processes that create natural diamonds are chaotic compared to the clinical conditions of a laboratory.

  • Lab-grown diamonds are cheaper than natural diamonds of a similar weight, colour and quality. So you get more bedazzle for your bucks.

What are man-made diamonds?


Man-made (or woman-made) diamonds are diamonds. They are made from carbon atoms - the same material as natural diamonds. They also have the same optical properties as a natural diamond. The carbon atoms in a diamond are arranged in a crystal structure known as a face-centred cubic or FCC lattice. Watch a video about how diamonds are made.


H2: History of man-made diamonds


Between 1879 and 1928, numerous scientists claimed they had made a diamond in a laboratory. None of these results were confirmed. It wasn’t until 1954 that the first lab-grown diamond was pronounced ‘the real thing’.


The science of lab-grown diamonds was advanced in the USA, Sweden and the Soviet Union. Howard Tracy Hall of the USA was credited with making the first man-made diamond in the world. He used a press that was capable of replicating the pressures and temperatures within the Earth.


How are lab diamonds made today?


Two methods are commonly used to make the best man-made diamonds: High Pressure-High Temperature (HPHT) and Chemical Vapor Deposition (CVD).


  • HPHT involves placing a small diamond ‘seed’ into a piece of carbon. This is pressurised to approximately 10 billion Pascals and heated to more than 1,450° C. The pressure and heat melt the carbon, which forms a diamond around the diamond seed.

  • CVD also uses a small diamond seed. The seed is put in a sealed chamber that’s filled with methane and hydrogen, then heated to 800° C. The gases are ionised into plasma, which breaks their molecular bonds and releases carbon. The carbon atoms stick to the seed and a new diamond is formed.


Man-made diamonds vs real diamonds


The naked eye, even if it belongs to a diamond specialist, cannot distinguish a natural diamond from a lab-made diamond. Only specialised equipment can reveal the tiny differences in trace elements and crystal formation.


Interestingly, man-made diamonds are more pure, in the true sense of the word. Natural diamonds encounter trace elements during their formation, while lab diamonds only involve carbon. However, sometimes trace elements are introduced to the laboratory process to create coloured diamonds. For example, nitrogen is added to make yellow diamonds.


The lab-made diamonds we sell at DOR always come with a gem certification that identifies them as laboratory grown.


Lab-grown diamonds vs diamond simulants


While ‘fake’ diamonds (such as cubic zirconia and moissanite) look like diamonds, they are not true carbon crystals. Unless your fake diamond turns out to be white sapphire, it will be worth a lot less than a lab-grown diamond.


Tests to determine whether a gem is truly a diamond (natural or lab-grown) include thermal conductivity, facet doubling, UV fluorescence and the fog test. Did you know that true diamonds won’t fog up? For loose gems, how long the stone takes to sink into a glass of water can reveal whether it’s a true diamond or not. Real diamonds sink very quickly.


FAQs about lab-grown diamonds


What are man-made diamonds called?

Diamonds made in a laboratory have a multitude of names:

  • Lab-grown diamonds

  • Cultured diamonds

  • Engineered diamonds

  • Man-made diamonds

  • Synthetic diamonds

  • Lab-created diamonds

  • CVD diamonds

  • HPHT diamonds

  • LGD diamonds

Are man-made diamonds real diamonds?

Yes they are. Like natural diamonds, they are made from pure carbon, crystallised in an isotropic 3D form.


Are lab grown diamonds GIA certified?

The Gemological Institute of America has been grading lab-grown diamonds since 2007. And since 2019, they have stopped using the word ‘synthetic’ to describe lab-grown diamonds. When GIA technicians are grading lab diamonds, they use the colour, clarity and cut grading scales that are used for natural diamonds. However, there is always a statement about how the diamond was made (CVD or HPHT). There are also other laboratories like IGI who also offer reputable lab-grown and natural diamond grading.


Can a jeweller tell if a diamond is lab-created?

A jeweller can use a Type 11a diamond tester, which is a device that determines whether the diamond is a 11a gem. Less than 2% of natural diamonds are 11a stones, so if the tester reveals that your diamond is a 11a, it’s probably lab-grown. To be 100% certain, the gem needs to be sent to a specialised gem lab for testing.


Should I buy a lab-grown diamond?

It’s a personal choice. If you want a stone that was made deep within the Earth millions of years ago and brought to the surface by a volcano, get a natural diamond. If you want a guaranteed conflict free diamond with potentially less environmental and ethical impact at a lower cost, get a lab-grown diamond.


Where to buy man-made diamonds?

DOR in Ponsonby has a large selection of lab-grown diamonds to choose from with GIA or IGI certification. Come and see us.


Are you looking for a lab-grown diamond engagement ring?

If you’re searching for ‘man made diamonds nz’ or ‘lab grown diamonds nz’, book an appointment at DOR to discover our beautiful lab-grown diamond engagement rings. Begin your diamond education at home with our The Diamond Buying Guide - The 4Cs of Diamonds. Then, get in touch with us to explore the sparkling world of DOR diamond engagement rings.