Mines
Copper is most commonly present in the Earth's crust as copper sulphide ores. Copper ores typically contain 0.5 to 2% copper and about half of the annual worldwide mining production is extracted from Latin American mines.
There are also a number of copper mines in the Black Sea region. Cumerio's smelter in Bulgaria is the natural outlet for these mines and sourced in 2005 51% of its concentrates feed out of the region, of which 36% from Bulgaria itself. This entails a significant logistic advantage for both Cumerio and the mines.