Reserves and Resources: Definitions *
Non-renewables such as minerals.
Reserves: Identified deposits which can be recoverable and sold at current market prices.
Resources: Potentially valuable deposits, including hypothetical or undiscovered deposits, including those available at much greater than current market prices

Identified Undiscovered
Known Districts Undiscovered Districts
Economic Reserves Hypothetic Resources Speculative Resources
Marginally Economic Marginal Reserves
Subconomic Subconomic Resources
* Source: Murck, Skinner, and Porter (1996) Environmental Geology, p. 326.