Lab Grown Diamonds
Lab-grown diamonds are diamonds that are created in a laboratory using advanced technology. Lab diamonds are chemically, physically, and optically identical to mined diamonds and have historically been referred to as "cultured" or "synthetic" diamonds.
In 2018, the Federal Trade Commission (FTC) declared that lab grown diamonds are equal to mined diamonds and should be described to consumers in the same way. This guidance was intended to ensure consumers are informed when making their diamond purchasing decisions.
How are Lab Diamonds Formed?
- High pressure-high temperature (HPHT)
- Chemical vapor deposition (CVD).
HPHT (High Pressure, High Temperature)
HPHT diamonds are lab-grown diamonds produced by simulating the high-pressure and high-temperature conditions found deep within the Earth's mantle. A small diamond seed is placed in a growth chamber with carbon-rich gases and a metallic catalyst. High pressure and high temperature conditions cause the carbon atoms to solidify around the diamond seed, forming a new diamond. The process can take several weeks to months, depending on the desired size of the diamond and the process can be controlled to produce colourless or coloured diamonds.
CVD (Chemical Vapour Deposition)
The CVD process starts with a small diamond seed, usually a natural diamond, which is then placed in a vacuum chamber. A mixture of gases, such as methane and hydrogen, are then ionized by using high-energy sources like microwaves or plasma to break down the gasses which release carbon atoms. The carbon atoms then settle onto the diamond seed, layer by layer, forming a new diamond. The process is carefully controlled to ensure that the carbon atoms settle onto the diamond seed in a way that produces a high-quality diamond. The process typically takes several weeks to create a single diamond, depending on the desired size of the diamond and the process can be controlled to produce colourless or coloured diamonds.
What are the main difference between CVD & HPHT lab created diamonds?
The main difference between CVD and HPHT lab created diamonds is the method used to grown them. CVD (chemical vapor deposition) diamonds are created using plasma containing hydrogen and methane. The gases are heated and broken down into ions of hydrogen and carbon which are then deposited onto the diamond’s surface at the atomic level. HPHT (high-pressure, high-temperature) diamonds are created from a natural diamond seed that is heated and pressurized to mimic the conditions in which naturally occurring diamonds are formed.
As the technology advances and the process refined, there are very few differences between them. In terms of the final product, HPHT and CVD lab-grown diamonds are very similar in appearance and properties, and both are considered real diamonds. However, there may be slight differences in their growth patterns and trace element concentrations, which can be detected through advanced gemological testing.