Ever since Archduke Maximillian in Austria proposed to Mary of Burgundy with a diamond ring in 1477, diamonds have been a popular choice for jewelers and consumers around the world. The $14 billion global rough diamond industry is projected to continue growing through 2030, which includes both diamonds used in industry as cutting tools and in jewelry. Natural diamonds are harvested in mines, but concerns about the harsh conditions faced by miners have caused controversy over the years. In an effort to find an alternative way to supply diamonds, some have turned to creating diamonds in laboratories.

About synthetic diamonds:

Synthetic lab-grown diamonds only currently account for about 1% of the market share so far, but their lower price point and cruelty-free claims have brought high-level investors, such as Leonardo DiCaprio, into the fold. Lab-grown diamonds are chemically equivalent to natural diamonds, unlike diamond simulants like moissanite which are stones that just physically resemble natural diamonds. Two of the most common technologies used to create diamonds are HPHT (high pressure, high temperature) and CVD (chemical vapor deposition).

HPHT mimics the conditions natural diamonds are created in: high pressure and high temperature. The process starts with placing small shards of diamond seeds and high-purity graphite powder inside a press. The three main types of press used are belt press, cubic press, and split-sphere press. The inside of the press is heated up to around 1500°C and pressurized to 5-6 GPa in the presence of metal catalysts until the carbon atoms from the graphite break apart and precipitate onto the diamond seeds to form larger diamonds. The process takes about 1-2 weeks as opposed to the billions of years it takes to grow natural diamonds, which could cause significant amounts of crystallographic defects and residual stresses to build up. This affects the suitability of HPHT diamonds in cutting tools because of the threat of micro-chipping in the tool.

CVD uses milder conditions to create diamonds, also starting with diamond seeds placed in a heated chamber. The chamber is also filled with gases like methane to act as a carbon source. The gases are ionized into plasma using lasers, microwaves, or other energy sources which cause the carbon atoms to latch onto the diamond seeds to form larger diamonds. The temperature required in the chamber is 600°C lower than that in HPHT, and the pressure required is much lower too. Furthermore, the composition of impurities in the diamond can be more easily controlled through controlling which gases are present in the chamber. CVD diamonds have only been in the market for a decade, but the quality and consistency has improved during that time and the much lower cost of production has continued to make it an attractive alternative to HPHT.

Competition with natural diamonds:

Many lab-grown diamond manufacturers borrow the 4C grading system of natural diamonds (cut, color, clarity, carats) when talking about their products, but the Gemology Institute of America (GIA) grades them differently and releases a report that looks different from the report issued for natural diamonds. Big natural diamond suppliers who have recently ventured into the synthetic diamond market, such as De Beers, are reluctant to even grade their synthetic diamonds to hammer home the distinction from their natural diamond products.

Synthetic diamonds sell at around 20-30% less than their natural counterparts, but they are increasingly difficult to detect, which presents a challenge to consumers who might not have the tools to distinguish between the two. Many worry that an increase in demand for synthetic diamonds at the expense of natural ones may be disastrous for countries that rely heavily on natural diamond exports, such as the Democratic Republic of Congo. However, the co-existence of markets for natural and synthetic gemstones like rubies and emeralds suggests that the markets for natural and synthetic diamonds can also develop in parallel without eating away at each other’s consumer base.

If you have any questions or would like to know if we can help you with your innovation challenge, please contact our Natural Resources lead, Eric Joyce at ejoyce@prescouter.com.