HPHT Diamonds
With the increasing need for ethical diamonds, scientists raced to attempt and create a diamond in the laboratory. This led to the creation of the first lab-grown diamond by General Electric (GE) in the early 1950s. The traditional method of creating lab-grown diamonds, HPHT, is known as the high-pressure, high-temperature method. It was a breakthrough invention which caused an uproar in the diamond industry and is continued to be used in the creation of lab-grown diamonds even today. Let us find out how diamonds are created using the HPHT method (Source: GIA).-
THE HPHT diamond growth process:
- A diamond seed is placed in a specifically designed press.
- The growth chamber is heated to 1300-1600 °C with pressures above 870,000 pounds per square inch.
- The molten metal dissolves the high-purity carbon source.
- Carbon atoms precipitate on a small diamond seed crystal, and a synthetic diamond begins to grow.
- The lab-grown crystal is then cut and polished by a diamond cutter.
CVD Diamonds
While the term ‘CVD’ might seem unfamiliar to you, it is fairly straightforward to understand. A CVD diamond is a new-age form of lab-grown diamond. These diamonds are grown in labs using a process called Chemical Vapour Deposition, or CVD. Let's learn about how these diamonds are created below. (Source: Queensmith).-
Chemical Vapour Deposition (CVD) diamond-making process:
- A thin diamond seed is selected and placed in a sealed chamber
- The chamber is heated to around 800°C and flooded with carbon-rich gas
- The gas ionises, breaking down into pure carbon
- The pure carbon molecules attach to the original diamond seed
- This process continues until a fully formed diamond is created
