Artisanal and Small-Scale Mining (ASM)
Artisanal and Small-Scale Mining (ASM)
The informal sector that supplies the majority of the world's coloured gemstones
Artisanal and small-scale mining — universally abbreviated in the trade as ASM — refers to mining operations characterised by low mechanisation, manual or semi-manual extraction techniques, limited capital investment, and, in most jurisdictions, informal or semi-formal legal status. Despite its modest technological footprint, ASM is the dominant mode of production for coloured gemstones globally: rubies from Mozambique and Myanmar, sapphires from Madagascar and Sri Lanka, emeralds from Zambia and Colombia, tanzanite from Tanzania, and a vast array of other species all reach the market predominantly through artisanal channels. The International Labour Organization estimates that ASM employs between 40 and 100 million people worldwide when dependants and downstream workers are counted, making it one of the largest sources of rural livelihood in the developing world.
Defining Characteristics
There is no single internationally agreed legal definition of ASM, and thresholds vary by country. In practice, the sector is identified by several consistent features:
- Extraction by hand tools — picks, shovels, sluices, and hand-operated pumps — rather than heavy earthmoving equipment.
- Small working units, typically family groups or informal cooperatives of fewer than a dozen individuals.
- Limited or absent formal title to the land or mineral rights being worked.
- Episodic or seasonal production, often responding to commodity price signals.
- Sale of rough material through multi-tier local dealer networks before export.
The distinction between ASM and large-scale mining (LSM) is not merely technical; it carries significant implications for environmental oversight, labour protections, revenue transparency, and supply-chain traceability — all matters of growing concern to responsible jewellery brands and their customers.
ASM and the Coloured Gemstone Supply Chain
Coloured gemstones are more dependent on ASM than virtually any other mined commodity. Unlike diamonds or base metals, where large corporate operations dominate production, the geological distribution of coloured gemstones — often occurring in remote, geologically complex deposits unsuited to industrial extraction — has historically favoured small-scale, labour-intensive methods. A significant proportion of fine rubies, sapphires, spinels, and tourmalines are recovered from alluvial or eluvial gravels worked by individual miners with hand tools and simple sluice boxes.
This structural reality creates a fundamental challenge for supply-chain due diligence. The chain from mine to market typically passes through local dealers (brokers or middlemen), regional trading centres, export merchants, cutting centres in Bangkok, Jaipur, or Hong Kong, and finally wholesale and retail markets — each step adding opacity. Tracing a sapphire to a specific ASM pit in Ilakaka, Madagascar, or a ruby to a particular working in Montepuez, Mozambique, remains technically and logistically difficult, though blockchain-based provenance pilots and field-level documentation programmes are beginning to address this.
Governance, Certification, and Reform Efforts
The principal international body working to formalise and improve ASM is the Alliance for Responsible Mining (ARM), a Colombian-founded non-profit that developed the Fairmined standard. Fairmined certification requires mining organisations to meet criteria covering legal compliance, environmental management, safe working conditions, and community benefit-sharing. Certified operations gain access to a price premium — the Fairmined premium — intended to fund social and environmental improvements at the mine level.
The Responsible Jewellery Council (RJC), whose membership spans miners, traders, manufacturers, and retailers, has developed a Chain of Custody standard that can encompass ASM-sourced material where adequate documentation exists. The RJC's Code of Practices addresses child labour, forced labour, health and safety, and environmental impact across all scales of operation.
Other relevant frameworks include the OECD Due Diligence Guidance for Responsible Supply Chains of Minerals from Conflict-Affected and High-Risk Areas, which, although originally focused on the so-called conflict minerals (tin, tantalum, tungsten, and gold), is increasingly applied by jewellery companies to coloured gemstone sourcing.
Challenges and Ongoing Debates
Critics of certification-led approaches note that the cost and administrative burden of achieving formal certification can exclude the very smallest and most marginalised miners — precisely those most in need of improved conditions. There is also a risk that formalisation efforts, if poorly designed, criminalise subsistence mining without providing viable alternatives, displacing communities rather than improving their circumstances.
On the environmental side, ASM operations — particularly those using mercury in gold recovery, or those working in ecologically sensitive riparian zones — can cause significant localised damage. However, researchers and development practitioners increasingly distinguish between the environmental footprint of ASM and that of large-scale industrial mining, noting that ASM's lower capital intensity often correlates with more limited, if still real, environmental impact per unit of production.
For gemmologists and trade professionals, the practical implication of ASM's dominance is that provenance documentation for coloured gemstones is frequently incomplete or absent, and that laboratory origin determination — offered by GIA, Gübelin, SSEF, and Lotus Gemology, among others — addresses geographic origin but cannot, by itself, confirm the conditions under which a stone was extracted.