Laboratory-Grown Diamonds


As you begin your research into diamonds, you may come across the terms lab-grown, man-made, or cultured diamond. These are used interchangeably across the jewellery industry and simply describe the scientific process of creating a diamond above-ground. If you are considering a lab-grown diamond for your forever-piece, we aim to provide you with the proper education so that you feel confident in this sentimental decision.

So, what is a lab-grown diamond? A lab-grown diamond is precisely that, a diamond. However, these are not created over billions of years within the earth's mantle but are grown under highly controlled laboratory conditions through advanced technology that has taken almost sixty years to develop. This technology replicates the earth's natural growth process of crystallising carbon, resulting in diamond crystal with variations in appearance and grading, just like diamonds formed naturally. They are chemically, optically and physically identical to Earth-mined diamonds and exhibit the same visual properties of fire, scintillation, and sparkle. Much like a natural diamond, the value is primarily determined by the carat weight and quality grading. However, you can expect a considerable price difference between the two.


There are two techniques commonly used by diamond growing laboratories:

- CVD (Chemical Vapour Deposition)
- HPHT (High-Pressure High-Temperature)

CVD Method

  1. Each diamond is grown from a tiny carbon 'seed' of a pre-existing diamond. This seed is placed into a growth chamber.
  2. A plasma ball of superheated carbon-rich (hydrogen and methane) gas is created in the chamber. The gases are ionised to break down their molecular bonds to allow the pure carbon to attach itself, layer by layer, to the diamond seed. Over a few weeks, a new, larger diamond is formed, completely identical to the diamonds found in nature.
  3. The diamond is then cut, polished, and graded by world-renowned laboratories.

HPHT Method

  1. A diamond 'seed' is placed in a specifically designed press, capable of generating very high pressures.
  2. A high-purity carbon starting material (such as graphite) is exposed to a high amount of pressure and heat. The carbon source dissolves in a flux of molten metal and migrates towards the diamond seed, and a diamond crystal begins to grow.
  3. The diamond is then cut, polished, and graded by world-renowned laboratories.


Lab-grown diamonds have essentially the same chemical composition, crystal structure, optical and physical properties as diamonds found in nature.

Mined diamonds are primarily composed of pure carbon; however, many diamonds contain traces of impurities, such as nitrogen or boron, acquired during formation. Diamonds that have little to no autonomic impurities are classified as type IIA (2a) diamonds. These gems have zero or exceptionally few nitrogen atoms within the crystal lattice structure and considered to be the purest and rarest form of diamonds. Around 1-2% of naturally formed diamonds are type IIA. All of our lab-grown diamonds are type IIA.


For some, there are concerns that arise over the environmental and human labour in the natural diamond mining process. This is not to say that natural diamonds are necessarily unethical, but consumers are invested in supporting a process that offers a long-term, sustainable practice, over the disruptive processes of diamonds pulled from the earth.


All diamonds are submitted to grading laboratories and are accessed on their quality. Like natural diamonds, lab-grown diamonds are primarily graded on the 4C's (carat, cut, clarity, and colour), along with the dimensions, proportions and relevant qualities of the stone. All lab-grown diamonds at LOUISE JEAN are analysed and graded by the world’s leading diamond laboratories such as IGI, GCAL and GIA.

A lab-grown diamond’s girdle is laser inscribed with the report number as well as the word 'lab-grown' or 'LG'. These steps are taken in the interest of clear delineation for consumers. It is a requirement that any gem material produced in a laboratory be described in a way that leaves no doubt that it was not produced naturally.