Ores

Ores are naturally occurring solid materials from which a metal or valuable mineral can be extracted profitably. The designation depends on economic viability as well as geology; a mineral may be an ore in one situation and not in another. Ores are typically composed of ore minerals embedded in gangue, or waste rock. Ore deposits form through concentration processes during geological activity, including magmatic differentiation, hydrothermal fluid flow, sedimentary concentration, and placer deposition.

Common ore deposits include iron ore (hematite, magnetite), aluminum ore (bauxite), copper ore (chalcopyrite, bornite), lead and zinc ores (galena, sphalerite), tin ore (cassiterite), and precious metal ores (native gold in various minerals). The exact mineral assemblage dictates the extraction and processing steps.

Mining removes the ore and ore grade measures metal content per ton. Beneficiation or ore dressing (crushing, grinding, separation) concentrates the valuable material. The concentrated ore is then subjected to smelting or direct reduction to extract metal, followed by refining to reach usable purity. Some metals are recovered through hydrometallurgical methods such as leaching.

Economically viable ore reserves depend on metal prices, mining and processing costs, and the ore grade. Environmental considerations include habitat disruption, energy use, and waste management. Ore geology and market dynamics together determine the scale and longevity of mining operations.