MR³ Index: Guiding the Conversion of Inferred Resources and the Transition to International Reporting Standards

The classification of mineral resources and reserves establishes a structured framework to quantify the contents of mineral deposits, covering continuity, grade distribution, tonnages, and the legal, technical, and economic feasibility of extraction within a defined timeframe and production rate. To reduce subjectivity and improve reliability, international reporting standards were developed on the principles of transparency, materiality, and competence. Compliance with these standards enables professionals and investors to evaluate mineral assets using consistent and comparable information across jurisdictions. Many mining operations are now seeking to align their disclosure practices with these frameworks to strengthen governance, improve credibility, and facilitate access to global capital. Within this context, the Mineral Re-sources and Reserves Readiness Index (MR³ Index) is introduced as a methodological tool to assess the degree of alignment of mining operations with international report-ing requirements. For operating mines, one of the key variables in the MR³ Index is the success in converting Inferred Mineral Resources directly into mine production, even in the absence of prior classification as Indicated or Measured Resources. This measure functions as a proxy for geological robustness and operational maturity. The applica-tion of the proposed methodology to an underground lithium mine in Brazil indicated a readiness level of 95.5%.