The evidence of whether mining truly helps local communities is mixed. For the most part, mining enriches local officials and the mining companies, not the local communities. 

Oxfam has found that mining negatively affects communities in a multitude of ways. The “resource curse” can force people from their homes, affect their food and water sources, change their societies and expose them to harassment. 

As recently as February 2016, drought-stricken Zimbabwean villagers are starving as they watch companies turn the ground over, collecting diamonds nearby.

Also: Africa is rich in diamonds but still poor.