Social and economic conditions, artisanal mining and the environmental consequences of land uses in part of the Territoire de Kamonia are described. The study area encompasses much of the drainage of the Longatshimo, Tshiumbu and Lubembe rivers, and extends from the Angola border to the Kasai River. Many of Gem Diamond's concessions are within this area, which covers about 3,600 square kilometres. It is estimated that approximately 306,000 people live in some 34,000 households in 184 settlements in the Kamonia study area. The majority (80-90%) of residents are immigrants or their offspring, these being people attracted by mining over the past 30 years. The remaining residents belong largely to the Tchokwe and Bakwafwiya tribes, which are the traditional occupants of this area of the DRC. All traditional chiefs are men of these tribes. The chiefs mainly settle disputes, allocate land and maintain authority to assure them and their families with incomes in the form of tributes from village residents. Each village is headed by a chef de village, who also takes a substantial proportion of profits (as a percentage of gravel) from mine areas (chantiers) that are not held by concessionaires. There are six major commercial centres in the area, each of which consists of more than one thousand households. Economic activity in two of the centres (Kamako and Kabungu) is greatly boosted by diamond trade with Angola. Most other towns or villages settlements are characterized by a greater or lesser mix of mining, trade and farming economic activity. An estimated 80% of people depend on incomes from mining, 15% on farming and 5% on trade. Most farm production is for domestic, subsistence use and is very largely the responsibility of women. Major crops are manioc and a variety of vegetables. There is very little livestock in the area. Most soils are nutrient-poor with the result that new fields are cleared frequently. The substantial cash incomes from diamonds support a large trade sector, consisting mainly of imported goods and some locally grown food. Most imports are transported by bicycles pushed over hundreds of kilometres. Each major commercial centre has several hundred enterprises consisting of market stalls, retail shops, diamond buyers and providers of telephone and money transfer services. Mining is concentrated on river deposits or on old alluvial terraces. Beyond differences between rivers and terraces, methods of mining depend largely on the ease of reaching diamond-bearing gravels and the kind of equipment available for mining. Gravel is divided in a variety of share-holdings between miners, their sponsors, concessionaires, local chiefs and some civil servants. The mining and trade of artisanal diamonds perhaps earns between $100-150 million for the Kamonia area. However, residents would be wealthier if leakages through payments for imported goods and as remittances to family members elsewhere in the DRC were lower. Considerable profits are also earned by traders once the diamonds leave the mining area. Conditions would also be improved if public funds from taxes on diamonds sales returned as government services or infrastructure. While some civil servants are present, there is essentially no public service or state infrastructure in the area. There has been substantial environmental degradation in the area, largely as vegetation loss by clearing for agriculture, firewood harvesting, charcoal production, bush fires, diamond mining and the expansion of villages. The extent of these impacts has been accelerated by population growth due to immigrants attracted by artisanal diamonds. Although artisanal mining has a poor reputation, it has improved the livelihoods of a great number of people. There are several ways in which Gem Diamond could further enhance these livelihoods. A more objective perspective on artisanal mining would also be in their interest, and perhaps that of the diamond industry as a whole.