Environmental impact of lab-grown diamonds

In addition to being faster and cheaper to manufacture, lab-grown diamonds are more environmentally and socially responsible than mined diamonds.

The two most popular methods for growing diamonds are high-pressure, high-temperature (HPHT) and chemical vapor deposition (CVD). In particular, a subset of CVD, microwave plasma CVD (MPCVD) is growing in popularity for diamond production, achieving a growth rate which is two orders of magnitude faster than HPHT.

Energy and water usage

When comparing the environmental impact of diamond manufacturing, everything is normalized in units of per carat of diamond while social impact is typically measured per employee over time. A study by Zhdanov et. al does a great job of comparing the energy and water use of mined, HPHT, and MPCVD diamonds by comparing ALROSA, DeBeers, GE, theoretical, and experimental values.

• Mining: ~96 to 150 kWh and 0.1 cubic meters of water per carat
• HPHT: ~28-245 kWh and negligible water per carat
• MPCVD: ~77 to 143 kWh and 0.003 cubic meters of water per carat

While the energy usage varies greatly by the exact setup for lab-grown diamonds, it is typically comparable to or less than that of mined diamonds.

Air pollution

A study by Frost & Sullivan in 2014 compared the relative air pollution impact of different diamond manufacturing techniques, distinguishing among carbon, sulphur oxide (SOx), and nitrous oxide (NOx) emissions. While carbon emissions (CO₂ and CH₄ particularly) are most often tracked as greenhouse gases, SOx is not often considered in emissions even though it contributes to acid rain, haze, and smog and thus is the air pollutant with the largest public health impact. Additionally, NOx warms the atmosphere 298x more than the same amount of CO₂ and 3.5x that of CH₄.

Mined diamonds were found to have 57 kg of carbon emissions per carat, while grown diamonds only had 0.028 grams per carat – a 10 million times reduction! SOx and NOx emissions were measured in tonnes for mined diamonds (0.014 and 0.042 tonnes respectively), but the same emissions were measured in mg for lab-grown diamonds at just 0.09 mg of NOx emissions and no SOx emissions. On average, lab-grown diamonds produce less air pollution than mined diamonds.

Safety

Additionally, lab-grown diamonds are found to be significantly safer for workers than mined diamonds. Whereas lab-grown diamonds have no reported lost time due to injuries or occupational diseases, mined diamonds have approximately 8 days per 100 employees lost due to injuries per year. Such mined diamond injuries often occur during landslides, mine collapses, and other accidents. They usually occur due to a lack of safety equipment.

Conflict-free labor and work exploitation

Although mined diamond safety has improved over the years, extending to community health issues like HIV/AIDS and tuberculosis, the issue on conflict diamonds remains. The Kimbereley Process, creating “conflict-free” diamonds, does not address worker exploitation. Health and safety conditions, child labor, and fair pay are not addressed. For example, it is estimated that 21% of children work in the Sub-Sahara region of Africa make approximately $30 per month, extending from mining in Africa to diamond polishing in India. In contrast, lab grown diamonds are conflict-free and sustainable.