What are Lab Grown Diamonds?

Real, certified diamonds, grown in a lab.


A lab grown diamond put simply, is a man made diamond. They are also sometimes known as engineered diamonds or cultured diamonds. They are chemically, physically and aesthetically identical to mined diamonds; and they're cut to the same high standard. They come certified by the same authority that certifies mined diamonds. They are absolutely the real deal.

The diamonds are grown in a lab setting using highly advanced technological processes that allow us to produce the identical conditions under which diamonds are found to naturally develop in the mantle. This process of mirroring the natural conditions that diamonds thrive in, provides us with the ability to ensure that the carbon atoms are arranged in a diamond crystal structure found in mined diamonds.

How are lab-grown diamonds made?

Lab grown diamonds are grown from 'seeds' - tiny diamond fragments that flower into flawless mature stones, thanks to the attention and expertise of skilled technicians working in cutting edge laboratories. A complex mix of gases is applied to the seed under high temperature, causing the diamond to grow, atom-by-atom, until a perfect gemstone as good as any mined diamond is formed.

There are only a few labs around the world are capable of producing gem-quality diamonds at the present time. However, scientists have been creating diamonds since the 1950s, replicating the conditions deep within the Earth by heating carbon to extreme temperatures while squeezing it in a hydraulic press. These diamonds were used in industry where visual properties were not important, but the hardness and conductivity were. It took research over several decades to cultivate large gem-quality stones. These were still not as large or as clear as the best mined diamonds, and most were coloured yellow or brown from the nitrogen required to stabilise the growing process. Today there are two methods to grow diamonds that are truly the same as mined diamonds, CVD (chemical vapour deposition) method and the HPHT (high pressure high temperature) method.

Lab grown diamonds grown by the Chemical Vapour Deposition (CVD) method start off in the lab as carbon seeds which act as a substrate on which the new stone can grow. The seeds are then placed inside an airless chamber. The chamber is then pumped full of ultra-pure carbon-rich gasses such as hydrogen and methane that become a plasma which causes the carbon atoms in the gas to separate and fall onto a diamond substrate, building up layers that ultimately result in a rough diamond crystal.

After this replication of the natural growing process, known as the diamond formation, crystallisation occurs and the lab grown diamonds mature in six to ten weeks. When a stone reaches a certain size it is put inside a second chamber and the diamond seed is excised from the crystal by laser to be reused to grow a new diamond. Just like with any earth mined diamond, it will then be cut, polished and graded within a lab by gemologists.

The HPHT method was the original method of creating lab-grown diamonds, first introduced in the 1950s. Diamonds grown by the HPHT method also begin with a small diamond seed that is placed into pure carbon. The diamond see is then exposed to intense pressure and heat in a chamber. The carbon melts which begins to form a diamond around the seed. The substance is then carefully cooled to form a diamond to be cut and polished just like a mined diamond. There are three tools used to to grow diamonds by the HPHT method in a lab. These are the cubic press, split-sphere (BARS) press and belt press. The belt press was first used to grow diamonds in a lab with more modern cubic and split-sphere presses introduced which are much more efficient in terms of yield as many larger, gem-quality diamonds have been produced using these methods.


One of our most frequently asked questions centres around whether lab grown diamonds are "real" and the answer is yes. They have the same atomic structure and the same physical, chemical and optical properties as mined diamonds. The difference with a lab grown diamond which makes people question their validity is their origin, with lab grown diamonds beginning in the lab and mined diamonds beginning in the earth’s mantle. However, the origin and the use of technology does not change the fact that both types of diamond of physically, chemically and optically identical. Lab grown diamonds are very different from other items that attempt to mimic the optical characteristics of a diamond such as diamond simulants. The notion that lab-grown diamonds are fakes or synthetic, is simply incorrect and lab grown diamonds are often misunderstood due to these labels people give them.

Lab-grown diamonds vs mined diamonds

Despite what many may believe, lab grown diamonds are virtually impossible to differentiate from diamonds mined from the earth. The only difference that lab diamonds display is a different trace element, however this does not alter the appearance of the diamond in any way and so will in fact display the same physical, chemical and optical characteristics of a mined diamond. The only way to examine this trace element and in turn, differentiate between the two types of diamond is by lab testing.

Given that lab diamonds possess the same physical, chemical and optical properties as a mined diamond, there is very little difference between them when it comes to choosing the best option for you. They both have an identical lifespan for example and both give off the same sparkling finish.

One advantage of a lab diamond over a mined diamond, is its value. Your money is likely to go further with a lab diamond and often reaches an impressive saving of 30-40%.

A further advantage relates to the ethical process of obtaining lab grown diamonds in comparison to mined diamonds. Not only is the carbon footprint significantly reduced by creating diamonds within a lab, but it also eliminates the effects of mining on the environment and the exploitive labour practices often involved with mining.

It is for this reason that they are often referred to as ‘conflict free’.

Lab-grown diamonds vs diamond simulants

Sometimes people confuse lab grown diamonds with diamond simulants such as cubic zirconia, moissanite, and others. The two are actually very different. A diamond simulant, whilst possessing the same optical characteristics of a diamond, are not actually carbon crystals and don't have the same chemical or physical properties as a diamond.

Lab grown diamonds on the other hand, are identical to diamonds in all three properties. Additionally, whilst you would need a lab to tell a lab grown diamond from a mined diamond, someone familiar with diamonds will be able to spot a diamond simulant with the naked eye.

Diamond simulants therefore have a lower value. This may therefore be of interest to those who want the look of a diamond for a lower price and aren’t too concerned about the actually properties of the simulant.

Lab-grown diamonds are made up of carbon atoms arranged in exactly the same structure you'd find in a mined diamond. Cubic zirconia, moissanite and other diamond simulants are not true carbon crystals - rest assured we never work with these diamond look-alikes. When you buy our lab diamonds you get the real thing.

More affordable

Lab-grown diamonds are more affordable than mined diamonds, so your money can go further if you choose a lab-grown diamond and you can get a higher quality stone for your budget. The saving can often be between 30-40% against a mined diamond of similar specifications and savings of up to 60% on coloured diamonds. The decision to buy a lab diamond is a decision to get a superior product for your money.


The CVD diamonds that Nightingale retail are grown in the USA. Lab grown diamonds made by the HPHT method are grown in Russia and India but, in our opinion, the CVD lab grown diamonds are superior so we only retail stones grown by this method.

In a Laboratory

By growing a diamond in a laboratory the whole process of carbon being transformed into diamond has been accelerated. Lab diamonds begin life in a chamber as a diamond “seed”. In the CVD chamber the same heat and pressure that create mined diamonds are replicated. The chamber is then filled with a hot plasma which has been electrically charged whereby atoms are freed with a positive charge and will attach to the diamond seed. This is the first step of growing the lab diamond seed into a beautiful diamond.

The Ethical Advantages

CVD lab grown diamonds are becoming more popular as public awareness increases. Some are excited by the science behind these stunning stones. Others are driven by the ethical advantages of buying a lab diamond. The carbon footprint is significantly reduced by creating diamonds in a laboratory. The negative impact on the environment of mining is no longer an issue and exploitative labour practices and creation of conflicts are avoided.

The Diamond Cutter

Lab grown diamonds are cut in a variety of weights. The diamond cutter will look at the rough crystal and cut the best quality stone that he can achieve from the rough diamond. This is exactly the same process for mined diamonds.

Smaller carbon footprint

Lab diamonds have a much smaller carbon footprint than mined diamond. Mining diamonds is an intense and destructive process. Mines can often be more than 3 miles in diameter and on average over 5 tonnes of earth must be removed for every 1 carat of diamond that is extracted from our planet. This is a similar story for precious metals such as gold. Every year, millions of tons of greenhouse gasses are emitted in the mining process, partially by the heavy diesel machinery used.

Conflict Free

Lab diamonds are essentially conflict free. Conflict diamonds are mined diamonds that are used either directly or indirectly as a currency to purchase arms and fund armies in and around their country of origin.

Further reading


Pearl Buying Guide

Prized and admired for millennia. As the first true gems ever to be used as adornments, the history of pearls in jewellery is nearly as old as the history of civilisation itself.

Read More

Diamond Grading Certificate

A diamond certificate is the evaluation by a third party accredited gemological laboratory of your diamond. In addition to the diamonds carat weight and measurements, a certificate includes grades for the diamonds cut colour and clarity.

Read More

Ring Sizing Guide

The last thing we at Nightingale want is to supply a ring and at the crucial ‘down on one knee’ moment it turns out to be too large or too small. Nightingale offer one adjustment free in the first three months.

Read More


It is mandatory in Great Britain for precious metals that meet the weight criteria to be assayed and hallmarked (stamped) to indicate the type and fineness of the metal.

Read More

Diamond Buying Guide

There are many beautiful gemstones that have been created by nature and mined from the earth but the most regal of them all is the diamond. The mysterious diamond is the most popular gemstone of them all and the one that has the most myths and legends associated with it.

Read More

Lab-grown Diamonds

A lab grown diamond put simply, is a man made diamond. They are also sometimes known as engineered diamonds or cultured diamonds. 

Coloured Diamonds

Nightingale can supply an outstanding collection of coloured diamonds loose or set within a bespoke or finished piece of Nightingale jewellery.

Read More