Mining is supposed to increase the nations’ and the peoples’ wealth, but unfortunately this is not usually the case in tropical Africa. Many children have to work in the mines and the security situation is gereally extremely bad. Often mining has detrimental effects on the environment: the forest is cut, soil and water are polluted, the increase of miners results in further deforestation, hunting of endangered species and social problems. In eastern D. R. Congo, militia often control mines (cassiterite, coltan, gold, diamonds) and use the proceeds for buying weapons.