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Ingle & Rhode launched in 2007 with the purpose of offering customers the most ethical engagement rings, wedding rings and other fine jewellery possible, and we remain committed to that mission to this day. But much has happened since 2007, with the world becoming increasingly aware of the threat posed by climate change and the pressing need to adopt sustainable business practices. So with this article, we explore the environmental impact of diamonds, and whether is it possible for them to be truly sustainable. In doing this we have tried to unpick the facts from the greenwashing, and hopefully give you a clear picture of the current situation and the future outlook.
What are sustainable diamonds?
Sustainability (noun): the ability to be maintained at a certain rate or level
For anything to be sustainable indefinitely, its production cannot depend on the consumption of finite resources (because by definition these will run out at some point) or have an environmental impact that is unsustainable or intolerable for humanity.
For these reasons, we use the following definition of sustainable diamonds:
“Sustainable diamonds are diamonds whose production does not consume finite resources and does not have an unsustainable environmental impact.”
This definition focuses on diamond production, but we should recognise that for diamonds to be completely sustainable, the whole supply chain including processing, logistics, marketing and sales also needs to be sustainable. However, the sustainability of the industry as a whole will depend on the transition of the wider global economy to clean energy, and an analysis of this is beyond the scope of this article.
Diamond mining is not sustainable
Natural diamonds are a finite resource
Irrespective of whether diamond mining is or could become environmentally sustainable, there are a fixed number of natural diamonds on the planet, so they cannot be mined indefinitely. At some point, all natural diamonds will have been mined.
In fact, it is estimated that there are about 1.8 billion carats of natural diamond reserves remaining globally (source: Statistica), and based on recent annual mining volumes (source: Bain & Company), we might reasonably expect these to be depleted within the next 20 years.
Diamond mining generates about 0.05% of all carbon dioxide emissions globally
Carbon emissions vary from one mine to another, but a study commissioned by the Diamond Producers Association in 2016 estimated that on average diamond mining produced about 160kg of carbon dioxide emissions per carat, though it should be noted that this figure is not the full picture, since it focuses only on diamond production, not the years of work entailed in developing a mine.
There were about 116 million carats of diamonds mined in 2021 (source: Bain & Company), meaning that diamond mining produced about 18.6 billion kg of carbon dioxide that year. While that’s a huge amount of carbon dioxide, it represents just 0.05% of total global emissions that year (source: IEA).
Eliminating carbon emissions from diamond mining will take a long time
Whilst diamond mining may only be a very small contributor to global carbon emissions it relies significantly on diesel-powered heavy equipment which will be very difficult (and therefore slow) to transition to clean sustainable energy sources.
Diamond mining has a very significant impact on the local environmental
Whilst diamond mining can be performed in a responsible manner, it is impossible to extract any mineral resource without having a significant impact on the local environment – at least temporarily whilst the mine is being built and operated.
The effects can be minimised and mitigated through careful planning and management, and the land and ecosystems can be restored after a mine reaches the end of its life, but nonetheless, diamond mining can cause localised soil erosion, deforestation, and a deterioration in water and air quality.
Types of sustainable diamonds
Lab-grown diamonds
Lab grown diamonds are made out of carbon (just like mined diamonds), and there is an estimated 1.85 billion, billion tonnes of carbon on earth. That's enough to make about 9.25 million, billion, billion carats of diamonds! So, in practical terms, carbon is not a finite resource, because it is extremely unlikely that we're going to run out!
This means that so as long as we power lab grown diamond production with clean sustainable energy, then lab grown diamonds can be sustainable.
Already, some lab grown diamond producers use 100% clean, renewable energy (solar and hydroelectric) making their lab grown diamonds sustainable. However, at present, the majority of lab grown diamond production globally is powered by electricity grids which depend to varying degrees on fossil fuels.
Indeed, currently, more than half of lab-created diamonds are grown in China (source: Statistica), which relies heavily on coal-powered generation of electricity. Coal is a heavily carbon-intensive fuel and as a result, carbon dioxide emissions per kWh of electricity in China are relatively high at 550g in 2021 (source: Statistica).
According to industry estimates, lab grown diamond production uses between 25kWh and about 250 kWh of electricity per carat, depending on the efficiency of the producers. This means that in the worst-case scenario, for Chinese diamond producers that use 250kWh of energy per carat, emissions are about 137.5kg of carbon dioxide per carat.
Many Chinese manufacturers' emissions will be lower than this, but even this worst-case scenario compares favourably with 160kg on average for diamond mining. It is also worth noting that carbon dioxide emissions per kWh have been falling steadily in China over the last ten years, and as China continues to transition to renewable energy over the next decade, the production of lab grown diamonds will become increasingly sustainable.
Meanwhile, electricity grids in many countries already have lower emissions per kWh than in China, and so producers in these countries compare even more favourably against the emissions from diamond mining. For example, in the US carbon dioxide emissions per kWh of electricity are 389g (source: EIA) and in the UK are 193g (source: bulb.co.uk).
Again the situation will only continue to improve as all countries transition to renewables, and encouraging new research suggests that this may happen at an accelerated rate in the US since it is now cheaper to build new solar farms or clusters of wind turbines and connect them to the grid than to keep operating 99% of existing coal plants in the US (source: The Guardian).
Carbon-negative diamonds
Although a handful of lab grown diamond producers are already 100% powered by clean, renewable energy, some pioneers have even gone a step further by creating carbon-negative diamonds!
There are two ways that they are achieving this: firstly, by generating more renewable energy than they are using (and supplying the excess to the grid, thereby reducing other users' emissions), and secondly, by capturing carbon dioxide from the atmosphere and using this as the carbon source from which they grow their diamonds.
Whilst both of these are wonderful developments, the first has by far the biggest environmental benefit since diamonds can only "capture" a tiny amount of carbon – a one carat diamond only contains 0.2g of carbon, which translates to the removal of just 0.7g of carbon dioxide from the atmosphere.
Recycled diamonds
One way in which all diamonds (mined or lab grown) can become sustainable is of course through recycling. So long as the environmental impact of the wider industry (e.g. sorting, processing, logistics, marketing, retail) becomes sustainable, the recycling of diamonds could in theory continue indefinitely. If you're interested in learning more, you can read our article about recycled diamonds.
The benefits of purchasing a sustainable diamond
Whether you choose to go with a lab grown diamond or a recycled diamond there are a number of significant benefits to choosing a sustainable diamond.
| Benefits | Comments |
| Reduce demand for diamond mining, thereby reducing its environmental impact and the health and safety risks to miners | Diamond mining has a significant impact on the local environment, as well as posing health and safety risks to miners. By purchasing lab grown or recycled diamonds, you are reducing the demand for diamond mining. |
| Reduce carbon dioxide emissions | Mined diamonds on average produce 160kg of carbon dioxide per carat, whereas lab grown diamonds at best produce zero carbon emissions and at worst produce less than 140g per carat. And as the world transitions to clean energy, the emissions from lab grown diamonds are falling faster than they are for mined diamonds. And recycling diamonds has low to zero carbon emissions too. |
| Avoid the risk of purchasing a conflict diamond | Some mined diamonds help to fund conflict. Although the Kimberley Process has gone a long way to reducing the number of so-called "blood diamonds" entering the market, it has not eliminated them completely. |
| More affordable than newly mined diamonds | Both lab grown diamonds and recycled diamonds cost considerably less than newly mined diamonds |
Is a sustainable diamond the same as an ethical diamond?
For a diamond to be ethical it needs to be more than sustainable. It also needs to be conflict-free and produced without human exploitation. In the case of lab grown diamonds, these are conflict-free and produced without human exploitation. For recycled diamonds, however, some of these may have originated in a conflict zone, and therefore could in theory be blood diamonds.
FAQs
What are sustainable diamonds?
Sustainable diamonds are diamonds whose production does not consume finite resources and does not have an unsustainable environmental impact. This includes recycled diamonds and some lab grown diamonds.
Are lab grown diamonds better for the environment than mined diamonds?
Yes. Diamond mining has a significant impact on the local environment in the vicinity of the mine site and greater carbon dioxide emissions than lab grown diamonds.
Are lab-grown diamonds sustainable?
Lab grown diamonds can be sustainable, and some already are. These are produced entirely with clean renewable energy. However, most lab grown diamonds currently contribute to carbon dioxide emissions, although the emissions per carat are falling and will continue to decline as the world transitions to renewables.
Are sustainable diamonds more expensive?
No. There are two types of sustainable diamonds: some lab grown diamonds, and recycled diamonds. Both of these are less expensive than mined diamonds.
What are carbon-negative diamonds?
Carbon-negative diamonds are lab grown diamonds whose production results in a reduction of carbon dioxide in the atmosphere. There are two ways of achieving this: firstly, by producers generating more renewable energy than they use (and supplying the excess to the grid, thereby reducing other users' emissions), and secondly, by capturing carbon dioxide from the atmosphere and using this as the carbon source from which they grow their diamonds.
Summary
It is clear that diamond mining is not sustainable, but sustainable diamonds do exist in the form of recycled diamonds and some lab grown diamonds (those produced with no carbon emissions, and those that are carbon-negative).
Even in the worst case, the carbon emissions from lab grown diamond production are lower than for diamond mining, and as the world transitions to clean renewables, emissions from all lab grown diamond producers will continue to decline.
