Deposit appraisal in mining is the systematic process of evaluating a known mineral deposit to determine its economic viability, technical extractability, and strategic value to a mining company or investor. It represents an intermediate stage of geological and economic assessment that follows initial discovery and preliminary exploration, but precedes the commitment of major capital to full feasibility studies or mine development. Deposit appraisal is conducted for bauxite, gold, iron ore, diamond, and other mineral deposits as a critical decision-making tool. The process typically involves a review and integration of all available geological data — including drill hole results, geophysical surveys, geochemical sampling, and geological mapping — to establish a preliminary understanding of the deposit's geometry, grade distribution, mineralogy, and structural controls. Resource estimation using geostatistical methods such as kriging or nearest-neighbor interpolation may be conducted to classify the deposit according to internationally recognized resource classification frameworks such as the JORC Code or NI 43-101. Deposit appraisal also encompasses preliminary assessments of metallurgical recovery, mining method suitability, infrastructure requirements, environmental constraints, and market conditions. For gold deposits, the appraisal considers ore grade, recoverable gold content, and treatment options. For iron ore, it addresses grade, impurity levels, and product specifications relative to market demand. For diamonds, the appraisal focuses on carats per hundred tonnes (cpht) and the estimated value per carat. The outcome of a deposit appraisal is typically a recommendation on whether to advance the project to prefeasibility study or abandon it.
