Some elements and resources are commonly referred to as rare, precious metals such as gold, silver and platinum being famous examples. However, there are some lesser known elements now integral to society which are becoming increasingly scarce on the world market. So, which elements should we really be worried about running out of?
In late 2011, the British Geological Survey (BGS) compiled a ‘risk index’, which ranked elements important to society based on relative supply risk. This rating system was designed to help people tell at a glance which elements were currently hard to come by. Factors which were taken into account in determining the risk index include scarcity, production concentration, reserve base distribution and governance. Each element was given a rating out of 5 on each of these criteria, with a score of 1 indicating the lowest risk, and 5 the highest.
Importantly, it can be seen that the rarity or supply risk of an element in this case does not necessarily directly correlate with the elements’ abundance on the Earth. An element, for example gold, may have a low crustal abundance giving it a high risk score of 5 in terms of scarcity, but it may also be evenly distributed across the globe. This gives gold, on average, a medium supply risk rating.
Conversely, an element that is not particularly scarce in the Earth’s crust may be listed as rare due to major producers reducing exports, creating a shortage on the market. The BGS risk list shows that China is responsible for the production of over 50% of all the elements on the list. Other important exporters include Australia, Russia, USA and Chile.
A spokesperson from the BGS, Andrew Bloodworth, has noted that though the scarcity of these elements may cause problems on a human scale, “we won’t run out of these metals any time soon.”
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Antimony
The most at risk element in the world, antimony has a rating of 9 in the relative supply risk index. A major use of antimony is fire-proofing, though it can be used for other applications such as paint chemicals and hardening lead.
The majority of antimony is produced in China, but the government has recently shut many major antimony mines and smelters for various environmental and political reasons. This had led to a worldwide dearth in the element. A low crustal abundance of 0.2 ppm also contributes to antimony having such a high rating on the risk index.
Though antimony is rare, there are many substitutes for its applications and several new antimony projects are being developed in Australia, Canada and Laos.
Antimony - Periodic Table of Videos
Platinum Group Elements
The platinum group elements are a collective of 6 transition metals: platinum, palladium, rhodium, ruthenium, iridium and osmium.
Though platinum is well known as a coveted metal for jewelry, it also has industrial applications, such as uses within catalytic converters.
Platinum and its associated metals have a BGS supply risk rating of 7.6. This is partly due to reserves being concentrated in South Africa, but also because the platinum group elements have such low crustal abundances in the first place.
Generally, platinum group elements can only be substituted by other platinum group elements. For example, palladium can be substituted for platinum in catalytic converters.
Platinum (version 2) - Periodic Table of Videos
Mercury
The platinum group elements are a collective of 6 transition metals: platinum, palladium, rhodium, ruthenium, iridium and osmium.
Though platinum is well known as a coveted metal for jewelry, it also has industrial applications, such as uses within catalytic converters.
Platinum and its associated metals have a BGS supply risk rating of 7.6. This is partly due to reserves being concentrated in South Africa, but also because the platinum group elements have such low crustal abundances in the first place.
Generally, platinum group elements can only be substituted by other platinum group elements. For example, palladium can be substituted for platinum in catalytic converters.
Mercury - Periodic Table of Videos
Tungsten
Tungsten is an essential component in the manufacturing industry, with applications ranging from drill bits to missiles.
As 83% of the global supply of tungsten is concentrated in China, this gives tungsten a high risk factor in terms of production concentration. Its risk index rating is 8.1. An element that is heavily concentrated in only one or two areas is always at risk of becoming scarce as primary suppliers of this element may decide to drastically reduce exports. This has in fact happened recently, with China stockpiling much more of its tungsten for internal use. The unique properties of tungsten mean that there are no known substitutes for its applications.
Tungsten (version 1) - Periodic Table of Videos
Rare Earth Elements
‘Rare earth elements’ are a group of metallic elements that have similar chemical properties. The group encompasses all 15 lanthanides, scandium and yttrium. These metals have the widest set of applications of any group of metals and are essential for the electronic, optical and magnetic industries.
Rare earth elements were once famously described as “neither rare nor earth.” This is accurate in one sense, as abundances in the earth of many rare earth elements are relatively high. However, the group of elements has an average rating of 9.5 on the supply risk index.
Once more, a major factor in the scarcity of rare earth elements is their uneven global distribution with 97% of all rare earths elements produced in China.
There are substitutes available for many of the uses of rare earth elements; however they are generally less effective.
Lanthanum - Periodic Table of Videos
Sources and Further Reading
This article was updated on the 24th May, 2019.
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