In the eastern Democratic Republic of Congo, a man descends a hand-dug shaft with a torch strapped to his head and a chisel in his belt. He may work that shaft alone or with a handful of relatives. He will carry ore up in a sack, wash it in a stream, and sell what he recovers to a local dealer before the week is out. This is artisanal and small-scale mining — usually shortened to ASM — and it is not a marginal curiosity. For certain materials, it accounts for a share of global supply that no trader or manufacturer can afford to ignore.
What the terms actually mean
There is no single legal definition that applies everywhere, but the broad distinction is consistent. Artisanal mining means individuals or small family groups working with hand tools — picks, shovels, pans, and simple sluices — typically without a formal licence. Small-scale mining involves a modest step up: a small company or cooperative, perhaps with a mechanical pump or a basic crusher, and often some form of permit. Both sit well below the threshold of what regulators and statisticians call industrial mining, which involves heavy machinery, long-term capital investment, and formal corporate structures. In practice, the line between artisanal and small-scale blurs, and the two are usually discussed together.
ASM is not confined to one country or one commodity. It is the dominant source of production for a few materials and a meaningful secondary source for many more. The commodities where it appears most prominently include gold, diamonds, coloured gemstones, tin, tungsten, tantalum, and cobalt. For some of these, the proportion coming from ASM is large enough that understanding the formal mining sector alone gives an incomplete picture of supply.
Why ASM exists where it does
ASM tends to concentrate where the geology is accessible and the economics favour a low-capital approach. Alluvial gold — fine particles carried by rivers and deposited in gravels — can be recovered with little more than a pan and patience. A formal mine would need to process many tonnes of hard rock to reach the same gold; an artisanal miner working a rich river bend can recover enough in a day to make the effort worthwhile at the individual level, even if the overall recovery rate is low by industrial standards.
Geography and governance also matter. ASM is most common in regions where formal employment is scarce, land tenure is uncertain, and the state has limited capacity to enforce licensing rules. This is not a coincidence of geology; it reflects the fact that where formal jobs and financial services are available, people generally prefer the security they offer over the hazards and unpredictability of hand-digging. ASM is, in large part, an economic response to limited alternatives.
An illustrative example: how recovery and volume interact
To see why ASM matters to a supply chain even when individual operations are tiny, consider an illustrative case. Suppose a mineralised area contains enough accessible ore that a population of artisanal miners collectively processes a meaningful volume each day. Each miner works at low efficiency — suppose, for illustration, that hand processing recovers only around half the metal present in the ore, compared with a much higher rate at a modern plant. Even so, if the number of miners is large, total recovered metal can be substantial. When analysts have tried to estimate this for cobalt in the DRC, for instance, the aggregate figure has at times been a significant fraction of national output, even though no single miner produces anything close to a tonne. Scale in ASM comes from people, not from machines.
The recovery shortfall matters too. Metal left in tailings by artisanal methods is lost to the supply chain permanently in most cases, because the economics of re-processing artisanal waste rarely work. This means ASM simultaneously contributes to supply and represents an inefficiency that industrial methods would, in principle, reduce — though building industrial infrastructure in remote or politically unstable terrain is far from straightforward.
What this means for supply chains
ASM supply enters the formal market through a chain of intermediaries. A miner sells to a local dealer, the dealer aggregates material and sells to a regional trader, the trader sells to an exporter or processor. By the time metal reaches a smelter or refinery, the original source is often obscured. This makes traceability difficult. A battery manufacturer in Japan or Germany buying refined cobalt sulfate may find it genuinely hard to determine what fraction of that material originated with an artisanal miner in Kolwezi.
This matters because conditions in ASM can be poor. Child labour, unsafe tunnels, exposure to toxic dust, and disputes over land and income are documented problems in some regions. Regulatory frameworks in consuming countries — including requirements that companies audit their mineral supply chains — have attempted to address this, but the intermediary chain makes verification hard in practice. Auditing a smelter is straightforward compared with auditing a hundred thousand individual miners spread across a remote province.
There is also a revenue dimension. Governments in producing countries collect tax and royalty income from licensed industrial mines with relative ease. ASM, operating partly or wholly outside formal licensing, often contributes little to government revenue even when its aggregate output is large. This affects what public investment a country can make from its resource wealth.
Responses and their limits
Various approaches have been tried to bring ASM into formal systems. Formalisation programmes offer miners legal status, access to better equipment, and in principle a route to safer working conditions and fair pricing. Certification schemes attempt to tag material as coming from verified responsible sources. Some industrial mining companies have established buying arrangements directly with artisanal miners in their concession areas. Results have been mixed. Formalisation requires miners to accept costs and constraints — fees, inspections, fixed selling points — that may not be offset by the benefits on offer. Where the informal market offers better prices or fewer bureaucratic demands, miners will use it.
The supply chain implication is that ASM is not a problem to be designed out in the short term. It employs a very large number of people, it produces materials that industrial buyers need, and it operates in conditions that make rapid transformation unlikely. Any honest account of where cobalt, artisanal gold, or tantalum comes from has to include it.
For readers going further
A reader with a professional or research interest will want to look at the structure of the intermediary trading chain in more detail — how prices are set at each node, how material is blended and re-classified, and what certified chain-of-custody schemes can and cannot verify. The relationship between ASM and formal mine concessions, including the legal and practical conflicts that arise when both operate on the same ground, is a distinct and technically demanding subject in its own right.