Mining is centered in Katanga province; products include copper, cobalt, zinc, manganese, uranium, cassiterite (tin ore), coal, gold, and silver. Diamonds are mined in Kasai. There are major deposits of petroleum offshore near the mouth of the Congo River. About 75% of Congo is covered with forest containing ebony and teak as well as less valuable woods.

Coltan is the industrial name for columbite–tantalite, a dull black metallic ore from which the elements niobium (formerly “columbium”) and tantalum are extracted. The niobium-dominant mineral is columbite, hence the “col” half of the term. The mineral concentrates dominated by tantalum are referred to as tantalite.