An ore reserve audit is an independent technical review conducted to verify that a company's reported Mineral Reserve estimates have been prepared in accordance with relevant industry codes and reflect reasonable, defensible geological and economic assumptions. Audits are typically performed by qualified, independent persons or competent persons as defined under reporting codes such as JORC, NI 43-101, or SAMREC, and are often required for stock exchange listing compliance, project financing, merger and acquisition due diligence, or periodic corporate governance review. The audit process generally involves reviewing drilling and sampling data quality, geological interpretation and modeling methodology, the statistical or geostatistical estimation techniques used, the modifying factors applied to convert resources into reserves, and the overall economic assumptions underpinning the declared reserve. For bulk commodities such as iron ore and bauxite, auditors place particular emphasis on verifying quality parameters affecting marketability. For gold, auditors scrutinize metallurgical recovery assumptions and cut-off grade sensitivity. For diamonds, reserve audits face the additional challenge of verifying bulk sampling representativeness and revenue-per-carat assumptions, given the inherent variability and subjectivity involved in diamond valuation compared to base or precious metal pricing.
