Cobalt is moderately rare. It ranks as the 32nd or 33rd most abundant element in Earth’s crust, present at roughly 30 parts per million. That puts it well behind common industrial metals like copper and nickel but far ahead of precious metals like gold or platinum. What makes cobalt feel scarcer than that number suggests is that it rarely forms its own ore deposits. Almost all cobalt is extracted as a byproduct of mining other metals, and the supply is heavily concentrated in a single country.
Cobalt’s Crustal Abundance Compared to Other Metals
At about 30 ppm in Earth’s crust, cobalt is roughly as common as lithium and significantly less common than nickel (the 24th most abundant metal) or copper. For context, iron sits at around 50,000 ppm, making it more than 1,600 times more concentrated than cobalt. Gold, by comparison, comes in at about 0.004 ppm, so cobalt is thousands of times more plentiful than precious metals.
The practical problem isn’t that cobalt is vanishingly rare in a geological sense. It’s that cobalt tends to be dispersed in small concentrations within other mineral deposits rather than forming rich, standalone veins. It shows up in minerals like cobaltite (a cobalt-arsenic-sulfur compound), siegenite, and carrollite, but these are almost always found alongside nickel, copper, or iron ores. Around 60 to 70 percent of global cobalt production comes as a byproduct of copper or nickel mining, meaning cobalt supply depends heavily on demand for those other metals.
Where Cobalt Comes From
The Democratic Republic of the Congo dominates global cobalt mining. The DRC holds roughly 6 million metric tons of identified reserves and produces more cobalt than any other country by a wide margin. This geographic concentration is one of the main reasons cobalt is treated as a “critical mineral” by governments around the world. A disruption in one country could squeeze global supply.
Australia holds enormous reserves on paper (over 100 million metric tons by some estimates), but much of that isn’t currently economical to extract. Other producing countries include the Philippines, Russia, Canada, and Cuba, though none come close to the DRC’s output. Total identified global cobalt resources sit at roughly 25 million metric tons, while proven reserves that can be mined economically total about 11 million metric tons.
A significant portion of DRC cobalt historically came from small-scale, artisanal mining operations. That share peaked around 2008, when artisanal miners accounted for an estimated 18 to 23 percent of world cobalt production. By 2020, that figure had dropped to 6 to 8 percent of global output, though artisanal mining remains a fixture of the DRC’s cobalt sector.
Why Cobalt Feels Scarcer Than It Is
Several factors combine to make cobalt behave like a much rarer resource than its crustal abundance would suggest. First, because it’s mostly a byproduct, miners can’t simply ramp up cobalt production when prices rise. They’d need to mine more copper or nickel, which has its own economics. Second, demand for cobalt has surged alongside the growth of lithium-ion batteries, which use cobalt in their cathodes to improve energy density and stability. Electric vehicles, smartphones, and laptops all rely on these batteries.
Third, the refining chain is concentrated. Even cobalt mined in the DRC is largely processed in China before reaching battery manufacturers. This adds another bottleneck. The combination of byproduct dependence, geographic concentration in mining, and processing concentration in refining creates a supply chain that’s more fragile than the raw geology would predict.
Deep-Sea Cobalt Resources
Vast quantities of cobalt exist on the ocean floor, locked in polymetallic nodules and cobalt-rich ferromanganese crusts. The Clarion-Clipperton Zone in the Pacific Ocean alone contains an estimated 21.1 billion dry tons of polymetallic nodules enriched with cobalt, nickel, copper, and manganese. Another 7.5 billion dry tons of cobalt-rich crusts sit in the Pacific’s Prime Crust Zone. By some estimates, the cobalt contained in these deep-sea deposits exceeds all known land-based reserves.
None of this is currently being mined commercially. Deep-sea mining faces enormous technical, environmental, and regulatory hurdles. But the sheer volume of these deposits means that cobalt’s long-term scarcity is more of an engineering and policy challenge than a geological one.
Cobalt in the Human Body
Cobalt plays a tiny but essential biological role. It sits at the center of vitamin B12, which your body needs for nerve function and red blood cell production. The daily requirement for B12 is only about 2 micrograms, so the amount of cobalt your body actually uses is minuscule. Humans don’t need cobalt in any other form, and excess exposure to cobalt compounds (from industrial settings, for instance) can be toxic.
How Cobalt Compares to Truly Rare Elements
Cobalt is not rare in the way that elements like rhodium, iridium, or helium-3 are rare. Those exist in the crust at parts per billion or less. Cobalt’s 30 ppm puts it in a middle tier: uncommon enough to command a premium, common enough that supply shortages stem from logistics and politics more than geology. For comparison, tin comes in around 2 ppm and is considered scarce, while zinc at roughly 70 ppm is relatively abundant. Cobalt sits comfortably between those benchmarks, which is why geologists describe it as “moderately rare” rather than truly scarce.
The real rarity of cobalt, in practical terms, is economic. Extracting it cheaply depends on the health of copper and nickel markets, the stability of the DRC, and the capacity of a handful of refineries. That combination of factors makes cobalt one of the most supply-constrained metals in the modern economy, even though the Earth contains plenty of it.