What are "ores"?

An ore is any naturally-occurring source of a metal that you can economically extract the metal from. Aluminum, for example, is the most common metal in the Earth's crust, occurring in all sorts of minerals. However, it isn't economically worthwhile to extract it from most of these minerals. Instead, the usual ore of aluminum is bauxite - which contains from 50 - 70% of aluminum oxide.

Copper is much rarer, but fortunately can be found in high-grade ores (ones containing a high percentage of copper) in particular places. Because copper is a valuable metal, it is also worth extracting it from low-grade ores as well. Ores are commonly oxides, for example:

• bauxite (Al₂O₃)
• haematite (Fe₂O₃)
• rutile (TiO₂ )

. . . or sulfides, for example:

• pyrite (FeS₂ )
• chalcopyrite (CuFeS₂ )