A Comparative Analysis of Energy and Water Consumption of Mined versus Synthetic Diamonds

What is it about?

In our research, we analyzed the energy and water consumption in diamond mining and laboratory synthesis operations. We used publicly available reports issued by two market leaders, DeBeers and ALROSA, to estimate water and energy use per carat of a rough diamond. The efficiency of the two most popular synthesis technologies for artificial diamonds—High-Pressure-High-Temperature (HPHT) and Microwave-assisted Chemical Vapor Deposition (M-CVD)—was examined. We found that the modern HPHT presses, with open cooling circuits, consume about 36 kWh/ct when producing gem-quality and average-sized (near-) colorless diamonds. ALROSA and DeBeers use about 96 kWh/ct and 150 kWh/ct, respectively, including all energy required to mine. Energy consumption of M-CVD processes can be different and depends on technological conditions. Our M-CVD machine is the least energy-efficient, requiring about 215 kWh/ct in the single-crystal regime, using 2.45-GHz magnetron for the support synthesis. The M-CVD methods of individual synthetic companies IIa Technology and Ekati Mine are different from our results and equal 77 and 143 kWh/ct, respectively. Water consumption for the HPHT and M-CVD methods was insignificant: approximately zero and 0.002 m3/ct, respectively, and below 0.077 m3/ct for ALROSA-mined diamonds. This study touches upon the impact of the diamond production methods used on the carbon footprint.

Featured Image

Photo by Daniele Levis Pelusi on Unsplash

Photo by Daniele Levis Pelusi on Unsplash

Why is it important?

Diamonds have many applications, and jewelry uses represent only a small portion of these. There has been an increase in demand for diamonds in electronic and optical industries, owing to their physical advantages far surpass those of other materials. These advantages include thermal conductivity, a high refractive index, the highest degree of hardness, nitrogen vacancies in the crystal structure, and boron doping. For these reasons, diamond is considered a promising material. However, the ecological impact of maintaining the supply of diamonds must be taken into account when considering the future use of diamonds. The ecological impact of diamond mining has been raised in mass media, with various players using different approaches to persuade potential clients—especially Generation-Z—that their diamonds (either mined or lab-grown) are more eco-friendly than those of their competitors. This study, therefore, focuses on the energy and water demands of the major diamond production methods, namely mining and lab-growing.

Perspectives