Tin, tantalum, tungsten and gold. All of these minerals are found in our electronics and all are considered conflict minerals, due to their potential origin in the Democratic Republic of Congo. While the African country contains an estimated $24 trillion in untapped mineral resources, it remains mired in poverty and violence, and mining these four metals can help fund armed conflict in the region.

But the metals are integral to consumer electronics. In a smartphone, for example, tin is used to solder metal components together, while tantalum is used in capacitors, which store electrical energy. Tungsten is used in the components that make a phone vibrate, and gold is used in circuit board connectors.