metalliferous
Containing a metallic element. Often used to describe ores that are mined commercially.
metalliferous: ore that's worth extracting metal from
A metalliferous deposit or ore body contains economically recoverable quantities of one or more metallic elements. The term does not simply mean that metal is present, but that the concentration and accessibility make extraction commercially viable. An ore is metalliferous when the cost of recovery falls below the market value of the metal it yields.
Metalliferous ores vary enormously in their metal content and form. A copper-bearing deposit might run at 0.5 to 2 percent copper by weight in disseminated porphyry ores, while high-grade hand-sorted cassiterite (tin oxide) might exceed 50 percent tin. Iron ore is often measured in iron percentage; magnetite deposits commonly contain 40 to 70 percent Fe. The host rock, gangue minerals, and degree of weathering all affect whether an ore body qualifies as metalliferous for a given metal and processing technology.
Metalliferous status depends on market price, mining depth, and available processing routes. A deposit rejected as uneconomical in one decade may become metalliferous when commodity prices rise or extraction technology improves. Oxide copper ores leach more easily than sulfide ores and thus tolerate lower copper grades. Heap leaching has made low-grade ores metalliferous where heap size and climate permit. Conversely, deep underground deposits of low-grade metal are often deemed non-metalliferous due to mining and haulage costs.
The term metalliferous is descriptive rather than compositional. Barren rock next to a rich vein contains metal atoms but is not metalliferous. The distinction matters to exploration geologists, mining engineers, and resource estimators, who must decide whether to mine, mill, or abandon a prospect. Metalliferous ore feeds smelters, concentrators, and leach heaps; non-metalliferous waste goes to tailings storage.
Usage extends beyond single metals. A polymetallic deposit yielding copper, molybdenum, and gold may be assessed as metalliferous for each metal independently. Some ores are metalliferous for one metal but treated as waste for another: molybdenum disulfide occurs in many porphyry copper mines but is recovered only where market strength justifies additional processing circuits.