Foreign investment in Africa's mineral resources has increased dramatically. This paper addresses three questions raised by this trend: do commercial mining investments increase the likelihood of social or armed conflict? If so, when are these disputes most prevalent? And, finally, what mechanisms help explain these conflicts? I show, first, that mining has contrasting effects on social and armed conflict: while the probability of protests or riots increases (roughly doubling) after mining starts, there is no increase in rebel activity. Second, I show that the probability of social conflict rises with plausibly exogenous increases in world commodity prices. Finally, I compile additional geo-spatial and survey data to explore potential mechanisms, including reporting bias, environmental harm, in-migration, inequality, and governance. Finding little evidence consistent with these accounts, I develop an explanation related to incomplete information—a common cause of conflict in industrial and international relations. This mechanism rationalizes why mining induces protest, why these conflicts are exacerbated by rising prices, and why transparency dampens the relationship between prices and protest.