An inferred mineral resource is the lowest confidence category of mineral resource estimation defined under internationally recognized reporting codes such as the JORC Code (Australia), NI 43-101 (Canada), and the SAMREC Code (South Africa). An inferred resource is that portion of a mineral resource for which tonnage, grade, and mineral content can be estimated with a low level of confidence, based on geological evidence and limited sampling, but for which there is insufficient data to verify geological and grade continuity or to reliably apply technical and economic parameters. In bauxite, gold, iron ore, and diamond mining, inferred resources are typically defined from early-stage exploration drilling or sampling programs where drill hole spacing is too wide to confidently establish the continuity of mineralization between sample points. For an inferred resource to be reported publicly, a competent person or qualified person (as defined under the relevant reporting code) must have reasonable prospects for eventual economic extraction, even though many uncertainties remain. Inferred resources cannot be directly converted to ore reserves and cannot support mine planning or financial commitments without first being upgraded to the indicated or measured resource categories through additional data collection and infill drilling. In diamond mining, inferred resources may be estimated from limited bulk sampling of kimberlite pipes or alluvial terraces, while in gold mining they often result from reconnaissance drilling programs along promising structural targets. Investors and analysts treat inferred resources with appropriate caution, recognizing that a significant proportion may not ultimately be converted to recoverable reserves due to geological complexity, grade variability, or unfavorable economic conditions.
