Mining in the jungle hinterland of Sierra Leone began in earnest during the 1930s, and the decade saw the industry grow at an extraordinary rate. In 1931, minerals had accounted for just 5% of total domestic exports; ten years later, that figure was 85%. The country, Britain’s oldest African territory, had been economically moribund for decades owing to a perceived lack of resources; the dramatic change in its fortunes came with the discovery of diamond deposits in the alluvial soil around the Sewa river, and by the eve of full independence in 1961 Sierra Leone would be producing fully a third of the world’s diamonds (Zack-Williams, 1982, 80; Smillie et. al., 2000, 18).

The first diamond to be found by a European in Sierra Leone was picked out of the gravel of the Gboraba stream, Kono District, in January 1930 by J. D. Pollett. His discovery was confirmed by N. R. Junner, an official of the Sierra Leone Geological Survey, which had been prospecting for heavy minerals, rather than precious stones. The discovery was made public, and though some gold mining companies at first failed to find any diamonds, the fields were more thoroughly examined by the Gold Coast-based and De Beers-handled Consolidated African Selection Trust Ltd. (CAST), who then applied for an exclusive prospecting licence in 1931.

Mining by hand began in 1933, and in 1935 a CAST subsidiary company, Sierra Leone Selection Trust (SLST), obtained a license from the colonial government for exclusive mining and prospecting rights throughout the entire country for 99 years. All such arrangements were made in close contact with the colonial authorities, who had early on determined that exclusivity and the control it guaranteed were the best way to maximise tax revenues from the nascent mines. Taxation on SLST’s diamond profits was set at 27%, eventually rising to 45% (ibid., 38, though SLST’s own literature reports a rate of 60%), and they also paid into development funds for the Kono District and elsewhere (SLST, 1965, 5. SLST’s own account has this latter figure at £25,000 in 1965, though Magbaily Fyle has the annual ‘mineral rent’ at £7000; Magbaily Fyle, 2006, 185). The contract had not been difficult to arrange, either with the authorities or the local chiefs: ‘Kono District had never been a commercially active region and Kono chiefs, who owned the land communally, appeared unconcerned and unable to grasp the dramatic impact that diamond mining would inevitably have’ (Smillie et. al., op.cit., 38)

The mining process had initially been of the simplest kind, with workers panning and washing the alluvial soil by hand, but SLST began mechanising their operation immediately after the 1935 contract was awarded, and by 1936 all SLST extraction was by means of mechanical pan plants (Greenhalgh, 1985, 52). By 1937, a million carats were being mined per year (Smillie et. al., op.cit., 3).

From 1948 onwards production was significantly intensified, but the situation remained stable until the ‘Great Diamond Rush’ of the 1950s, when the SLST concessions were almost completely overrun by illicit mining. Between 1952 and 1955 the amount of people working in the diamond areas went from 5000 to 50,000, almost all the increase being accounted for by illegal mining (‘illegal’ insofar that SLST had an absolute monopoly on all diamond mining in the country). The numbers were such that SLST’s monopoly was effectively broken; millions of pounds worth of precious stones were draining out of the country as the illegally mined diamonds were smuggled into Liberia. In a move which essentially legalised the diamond rush, new legislation passed in 1955 cancelled SLST’s original 99-year grant, compensated them with £1.6 million, and left them in control of around 450 square miles. The rest of the country was restored to the Government, which could then grant new licences under the new Alluvial Mining Scheme (AMS) (van der Laan, 1965, 10-16).

1500 new licences were granted in the first month of the AMS, and by 1956 up to 75,000 people were working the diamond fields, a mass movement of people and labour away from agriculture so serious that food production in the country noticeably suffered – Cartwright notes that ‘as many men left the land in a three-year period to search for diamonds as had left it over half a century to seek wage employment’ (Smillie et. al., op. cit., 41; Cartwright, 1970, 69). With tens of thousands of young men having moved to the diamond areas, serious social problems were also generated. The production of diamonds was largely pre-industrial by nature, and without the contracts, disciplinary controls and close regulations of truly industrialised migratory labour (such as those that pertained in the mines of South Africa or the Copperbelt, for instance), large swathes of the diamond country were reduced to ‘near anarchy, with armed bands of as many as 400 to 500 men raiding the SLST and licensed miners’ areas, and on occasion doing battle with the police’ (ibid.). 

Van der Laan suggests a major cause of the acceleration of the diamond rush of the mid-1950s was the fact that ordinary Sierra Leoneans realised that diamonds were easily obtained by simple means, often in areas close to their homes (van der Laan, op.cit, 64). It does however seem likely that this realisation might have been spurred by the new constitution of 1951, which for the first time allowed an African majority on the Legislative Council and African representation on the Executive Council. One of the first major issues to be debated by these new African members of the Sierra Leone government was the profits and structure of the mining companies, which had hitherto been shrouded in mystery, and it seems reasonable to suppose that this increase in public knowledge about the mining companies and their profitability may have contributed to the flood of unauthorised diamond diggers into SLST areas (ibid., 2-3). Another contributing factor may have been the profitability of thefts made from within operating SLST concessions. The existence of a ready market for smuggled diamonds in Liberia further encouraged illicit mining, and throughout the 1950s an influential network of Lebanese middle-men, local gang-masters and Liberian criminal elements all staked their claims alongside SLST to Sierra Leone’s diamond wealth.