Aluminum prices soared to a new decade high after a military coup in Guinea stoked concerns over the supply of bauxite, a sedimentary rock with high aluminum content, according to Bloomberg. 

Aluminum prices increased in London and Shanghai. London Metal Exchange (LME) contracts rose nearly 2% to $2,775 on the news of the military coup in the West African country on Sunday that could threaten bauxite supply. 

According to UK-based commodity research firm Marex, Guinea is one of the world's largest bauxite exporters. The country mines about a quarter of the world's supply. So far, there are no signs yet of supply disruptions.