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Alluvial Diamond Mining Project
What is Alluvial Mining?

What is Alluvial Mining?

Today, diamonds are mined in about 25 countries, on every continent but Europe and Antarctica (AMNH, 2006). Although most diamond mining is accomplished by large companies, in many developing countries, diamonds and other minerals are extracted by small- scale miners working in the informal sector. These small-scale miners often use simple artisanal mining techniques in alluvial deposits.

The process of alluvial diamond mining involves digging and sifting through mud, sand and gravel using shovels, sieves, or even bare hands. Typically, diamonds come from geologic rock formations called Kimberlites. Kimberlite rock formations that contain diamonds are eroded over time by rivers and streams and can deposit diamonds in the sediments carried by those streams farther downstream from the original source rocks. These deposits are called alluvial diamond deposits. The locations of these alluvial diamond deposits are controlled by the surrounding topography, drainage patterns, and the location of the Kimberlites themselves. Alluvial deposits are often mined and exploited by small-scale miners using artisanal mining techniques.

Artisanal mining techniques result in working with simple tools and equipment, usually in the informal sector, and outside the legal and regulatory framework. Artisanal operations are characterized by low productivity, lack of safety measures and high environmental impact. As a result, the majority of the artisanal miners are very poor, exploit marginal deposits with minimal returns, and are exposed to harsh and often dangerous conditions (IIED, 2006).

Artisanal and small-scale mining occurs primarily in rural areas where it represents the most promising, if not the only, income opportunity available. However, the mining activities are often viewed negatively by governments, large companies, and environmentalists. The use of child labor, the potential for environmental degradation, the high incidence of prostitution in mining camps, and the associated spread of HIV/AIDS where migrant workers are involved are major concerns in the artisanal mining sector. Further, the potential use of ASM revenue to finance conflicts and insurgencies in host countires or even regional scale conflicts is a major international concern. The use of diamond mining revenue to finance conflicts has been termed “conflict diamonds” or “blood diamonds”.

References

American Museum of Natural History. 2006. The Nature of Diamonds: Alluvial Mining. Accessed online at http://www.amnh.org/exhibitions/diamonds/alluvial.html

International Institute of Environment and Development. 2006. Artisanal and Small Scale Mining. Accessed online at http://www.iied.org/mmsd/mmsd_pdfs/finalreport_13.pdf

 


Alluvial mining using a pan. Imagery courtesy of Craig Chesek, U.S. Geological Survey Library, Reston, VA.

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