Always liked the USGS take on mineral reserves. > Reserves data are dynamic. They may be reduced as ore is mined and (or) the feasibility of extraction diminis

Always liked the USGS take on mineral reserves. > Reserves data are dynamic. They may be reduced as ore is mined and (or) the feasibility of extraction diminishes, or more commonly, they may continue to increase as additional deposits (known or recently discovered) are developed, or currently exploited deposits are more thoroughly explored and (or) new technology or economic variables improve their economic feasibility. Reserves may be considered a working inventory of mining companies’ supplies of an economically extractable mineral commodity. As such, the magnitude of that inventory is necessarily limited by many considerations, including cost of drilling, taxes, price of the mineral commodity being mined, and the demand for it. Reserves will be developed to the point of business needs and geologic limitations of economic ore grade and tonnage. For example, in 1970, identified and undiscovered world copper resources were estimated to contain 1.6 billion metric tons of copper, with reserves of about 280 million tons of copper. Since then, about 600 million tons of copper have been produced worldwide, but world copper reserves in 2021 were estimated to be 880 million tons of copper, more than triple those in 1970, despite the depletion by mining of much more than the 1970 estimated reserves. https://pubs.usgs.gov/periodicals/mcs2022/mcs2022-appendixes.pdf https://pubs.usgs.gov/periodicals/mcs2022/mcs2022-appendixes... Appendix C to 2022 Lithium Statistics and Information. https://www.usgs.gov/centers/national-minerals-information-center/lithium-statistics-and-information https://www.usgs.gov/centers/national-minerals-information-c...