We've been playing around with mercury since around 7,100 BC when we first daubed red paint made from mercury sulphide onto cave walls in Turkey. The mercury sulphide came from natural deposits of a volcanic mercury sulphide ore called cinnabar. The bright red ore was ground into a fine powder and used to colour paints, dyes, lacquers, and even cosmetics. At some point we also discovered that heating the ore caused an element in it to vaporise, and that subsequently collecting and cooling this vapour produced a shiny, liquid metal that has fascinated us ever since! We likened it to 'quicksilver', and to a god noted for his 'quicksilver' ability to move, and called it Mercury.
Spain - A Long Tradition Of Cinnabar Mining
Although cinnabar mines existed throughout the ancient world, the largest and oldest continuously operational ones are at Almadén in Spain where cinnabar mining commenced during Roman and Celtic times. In their heyday, these mines were responsible for supplying large civilisations like the Roman Empire with most of their cinnabar. The last Almadén mine closed in 2002 but not before the area had produced some 250,000 metric tons of mercury during its 2,000-year life span. The mine and its associated buildings are now a UNESCO World Heritage site under the Mercury category, and a mining tourism destination.
On the other side of the world, in a region in what is now California, there is another mercury mine with an almost identical name. The cinnabar deposit on which the mine sits was supplying the local Ohlone tribes with red powder for their paints and cosmetics long before people from other countries moved in.
Mexican settlers were first. They arrived in the 1820's and quickly established a mine on the local cinnabar deposit. The mine was called the New Almadén Mine after the one in Spain. By the time it was closed in 1976, it had produced 1,137,727 flasks of mercury for a total of 38,090 metric tons with a market value of over US$70 million. As with the Spanish mine, the New Almadén Mine workings and infrastructure are now a heritage park and mining tourism destination.
Current Cinnabar Producers And Reserves
China has been responsible for over 90% (some 3,400 metric tons in 2020) of the mercury produced in recent years. Second placed Tajikistan produced a mere 100 metric tons by comparison. Mexico produced 60 metric tons, much of it reclaimed from the silver laden mining waste left behind by colonial Spanish miners. A handful of other nations make up the balance, with low double digit quantities.
There are still some 600,000 tons of elemental mercury locked up in cinnabar ore reserves around the world, most of it in Spain (which still has the largest reserves). Other significant reserves can be found in China, Russia, Kyrgyzstan, Slovenia, Ukraine, Mexico, and Peru. Digging it up, processing, and using / selling it however is now highly scrutinised and increasingly regulated, or at least it's meant to be!
There are several global agreements in place whose purpose is to try and regulate the mercury industry. The most recent, and ostensibly the one with the most 'bite', is the UN's 2013 Minamata Convention on Mercury with its 131 ratifying countries (at the time of writing). Interestingly, both China and Mexico are on the list of ratifying signatories yet illicit mercury mining and use in both countries continues almost unabated. It seems these agreements and increased official scrutiny have simply driven some sectors of the mercury market further underground where it will be harder to root them out.
Winding Down Cinnabar Mining
Officially, cinnabar mining along with the import and export of elemental mercury and many mercury-containing products has been formally abolished or significantly reduced in most countries courtesy of agreements like Minamata. By 2019, documented industrial mercury use had fallen by around 50%. However, according to Statista1 and the US Geological Survey2, some 3,700 metric tons of mercury was still produced globally in 2020. Around 67% (just under 2,500 metric tons) is estimated to have come directly from cinnabar mining. This is double what was being mined before demand officially halved so clearly there has been a concerning rise in 'unofficial' demand!
The primary culprits in this regard appear to be small-scale and artisanal miners. Artisanal mining in particular is rife across many countries in Asia, Africa and Latin America, including China and Mexico. It has grown substantially in recent times as desperately poor people in these regions seek to eke out a living as best they can. Gold is an especially attractive target due to its high price and inexpensive, easy extraction processes. So attractive in fact that artisanal gold mining (AGM) now accounts for about 20% of total global gold production.
Artisanal gold miners however like to use mercury, especially in poor countries and remote locations. It's easy to use, doesn't require elaborate equipment in their unregulated mining world, is relatively easy to buy despite increasing regulation, and does an exceptionally good job of extracting gold. As AGM becomes more prolific, it drives up demand for mercury…. A classic demand and supply scenario in fact!
Artisanal Cinnabar Mining
Unsurprisingly, this rise in artisanal gold mining with its increasing demand for mercury has led to a corresponding rise in artisanal cinnabar mining to keep these miners supplied with said mercury. This is despite Articles 3 and 7 of the Minamata Convention that seek to end mercury trading (3) and reduce the use of mercury in artisanal gold mining (7) in signatory countries.
Similarly, cinnabar mining in its own right has become highly attractive to artisanal miners. The price of the silvery liquid metal, sold in 2 litre flasks, has soared over the past decade, hitting 4 digit figures ($US) per flask in 2011 and remaining there ever since.
Cinnabar lends itself well to artisanal mining – it is often found as rich, small, near surface deposits that are easy to find, access, and dig up. Extracting the elemental mercury from the ore likewise can be done easily, unobtrusively, and inexpensively in large wood-fired brick ovens. The resulting liquid can then be sold for cash into the black market where it supplies artisanal miners and various other end users that buy products via these channels.
Elemental Mercury And The Risky Business Of Artisanal Mining
Artisanal mining per se is risky, on several fronts. First, it is now illegal in many jurisdictions, especially in its current unmonitored format, and this carries a whole set of legal risks on its own. Second, it is also largely unregulated and unmonitored, leading to dangerously risky mining practices that harm both those who do it and the environment. PPE is virtually non-existent, extraction methods and equipment are lax and primitive, and dangerous chemicals are, more often than not, released directly into the environment.
In fact, artisanal mining, particularly gold, has been identified as the single "largest [global] source of anthropogenic mercury emissions"3 . It (artisanal mining) accounts for over one third (37%) of total global mercury emissions each year courtesy of the annual estimated average 2,058 tonnes of mercury it 'loses'3 ie uses and discards into the environment via atmospheric and fluvial emissions. This makes it a bigger concern than coal-fired power stations and their association with the highly toxic organic methylmercury, currently considered the most predominant source of mercury contamination confronting more densely populated areas!
Should artisanal mining be banned? Doing so would certainly solve some serious environmental issues! However, it would be extremely hard to do as many of these miners operate in remote areas where law enforcement is either non-existent or very haphazard. Further, despite what they're doing, and the harm it is doing to the environment, these people need to earn a living. Perhaps a better solution would be training, assistance with setting up safe compliant operations, and regulations (policed and enforced) that are designed to help this sector of the mining industry become 'better mining citizens' rather than wiping them out completely.
- Average price of mercury from 2012 to 2020
- Mineral Commodity Summary 2020
- Mercury Challenges in Mexico: Regulatory, Trade and Environmental Impacts