heavymineral

Heavymineral is a term used in geology to describe minerals that have relatively high density, typically above about 3.0 g/cm3. In sedimentology and economic geology, heavymineral concentrates form when transport processes sort detrital material by density. Lighter minerals are removed more readily, enriching the residue in high-density minerals that accumulate in placers, beach sands, and dune deposits.

Common heavy-mineral species include zircon (ZrSiO4), ilmenite (FeTiO3), magnetite (Fe3O4), rutile (TiO2), and garnet (a group with densities around 3.5–4.3). Other frequently encountered minerals are monazite ((Ce, La, Th)PO4), titanite (CaTiSiO5), as well as tourmaline and apatite. Their usefulness varies: zircon is widely used for U–Pb dating; ilmenite, rutile, and magnetite are important titanium-iron minerals; monazite can host rare earth elements and thorium.

Economic heavy-mineral deposits occur most notably as heavy-mineral sands along coastlines and in river systems. Major producers include regions in Australia, South Africa, and India. Mining typically employs gravity separation to produce a heavy-mineral concentrate, followed by magnetic and electrostatic separation to isolate minerals such as ilmenite, rutile, zircon, and monazite. Further processing may refine individual minerals for industrial use or extract rare earth-bearing minerals.

Heavy-mineral assemblages are valuable for provenance studies, helping to interpret sediment sources, transport pathways, and tectonic settings. Their grain morphology and chemistry, together with associated minerals, provide clues about erosion, weathering, and basin history.

Environmental and regulatory considerations influence heavy-mineral mining, especially in coastal environments. Best practices aim to minimize habitat disruption, manage water use, and rehabilitate mined areas.