Following the intriguing but oversimplified graphic on materials scarcity published by New Scientist (a graphic that turns out to be 2 years old, by the way), this in-depth article at the Oil Drum Europe (original article here) gives a well founded look at the problem of metal minerals scarcity. Especially interesting is the link between energy and minerals:
“In case of unlimited energy supply, metal minerals extraction would only be limited by the total amount of mineral resources. However, due to the scarcity of energy, the extraction rates of most types of metal minerals will cease to follow demand. Probably the only acceptable long-term solution to avoid a global systemic collapse of industrial society, caused by these resource constraints, is a path towards managed austerity. Managed austerity will have to be a combination of changes in technology and changes in both individual and collective human behaviour.“
Related: Historical statistics for mineral and material commodities.