With all due respect Miskealp1, grade is only one factor to take into consideration when deciding to proceed with opening a mine. The others in no particular order of importance are as follows:

• tonnage
• mining rate
• metal/commodity prices
• recoveries
• capital costs
• cost of capital
• mining costs
• mill, smelter, refinery costs
• transportation costs
• royalties payable
• site remediation costs

Plus there are probably a few more.

Respectfully submitted

geoprof