Coltan is used primarily for the production of tantalum capacitors, used in many electronic devices. Many sources mention coltan's importance in the production ofmobile phones, but tantalum capacitors are used in almost every kind of electronic device. Limitless water, from the world's second-largest river, the Congo, a benign climate and rich soil make it fertile, beneath the soil abundant deposits of copper, gold,diamonds, cobalt, uranium, coltan and oil are just some of the minerals that should make it one of the world's richest countries. As such, the Mining industry of the Democratic Republic of the Congo is a significant factor in the world's production of cobalt, copper, diamond, tantalum, tin, and gold as well. It is the Democratic Republic of the Congo's largest source of export income. In 2009, the Democratic Republic of the Congo (DRC) had an estimated $24 trillion in untapped mineral deposits, including the world's largest reserves of coltan and significant quantities of the world's cobalt. However the environmental degradation of the country and exploitation of its people is rarely reflected on.