An ore classification system is the structured framework used by geologists and mining engineers to categorize mineralized material according to its confidence level, economic viability, and physical or chemical characteristics. The most widely recognized frameworks are the CRIRSCO-aligned codes such as JORC (Australia), NI 43-101 (Canada), and SAMREC (South Africa), which divide mineralization into Mineral Resources (measured, indicated, inferred) and Mineral Reserves (proven, probable) based on geological knowledge and economic certainty. Within an operating mine, ore is also classified internally by grade bands, mineralogy, or metallurgical behavior. In bauxite mining, classification often separates gibbsitic from boehmitic ore because they require different refining temperatures in the Bayer process. In gold mining, ore is classified as free-milling or refractory depending on recovery difficulty. Iron ore is classified by Fe content and impurity levels such as silica, alumina, and phosphorus, which determine its suitability for direct shipping or beneficiation. Diamond-bearing material is classified by kimberlite facies and weathering grade, since these influence diamond liberation and recovery efficiency during processing.
