Butcher, according to a paper published by Edison Investment...

Butcher, according to a paper published by Edison Investment Research in Jan 2010 (Gold was about $1,000 back then)

"We have re-run our analysis to determine differentiated values for ‘measured’, ‘indicated’ and ‘inferred’ resource ounces to include the Canadian, Australian and South African markets as well as the London one. In doing so, we have been able to determine that the average value of a ‘measured’ resource ounce globally is US$340/oz, while that of an ‘indicated’ ounce is US$159/oz and that of an ‘inferred’ ounce is US$34/oz (excluding Witwatersrand ounces)."

Maybe someone else has a valuation mechanism for copper?