Mineral reserve definition
/What is a Mineral Reserve?
A mineral reserve is that portion of a mineral resource that is economically mineable, based on assessments and other information. The mineral reserve classification can be broken down further into the classifications noted below:
Proven reserves. Proven reserves are reserves where the size, shape, depth and mineral content of reserves are well-established.
Probable reserves. Probable reserves are similar to proven reserves, but the sites for inspection, sampling, and measurement are farther apart or are otherwise less adequately spaced. Probable reserves are based on data from drilling, sampling, and other exploration methods, though they may rely on assumptions about future conditions, such as prices or extraction technology.
Possible reserves. Possible reserves are those unproven reserves which an analysis of the data suggests are less likely to be recoverable than probable reserves. These reserves have a successful extraction likelihood of at least 10%, on the assumption that extraction work is conducted under normal conditions, using existing equipment.
The development phase of a mine is considered to have begun when management concludes that commercially recoverable mineral reserves exist, and has decided to develop the mine.
Related AccountingTools Course
FAQs
How Do Commodity Prices Affect Mineral Reserves?
Commodity prices directly impact whether a mineral deposit is economically viable to extract. When prices rise, more of the deposit may be classified as a reserve because the higher revenue justifies mining lower-grade or harder-to-access ore. Conversely, when prices fall, portions of the deposit may no longer meet profitability standards, reducing the reported reserve size.