A heavy mineral is a mineral with a relatively high specific gravity, typically greater than 2.9, compared with common rock-forming minerals such as quartz and feldspar. Heavy minerals are important indicators in mineral exploration because they can be concentrated by natural geological processes and often occur in association with economically valuable mineral deposits.
Examples of heavy minerals include magnetite, ilmenite, rutile, zircon, garnet, chromite, monazite, and gold. These minerals are resistant to weathering and erosion, allowing them to accumulate in river sediments, beaches, alluvial deposits, and placer deposits. In diamond exploration, heavy mineral surveys are widely used to identify indicator minerals such as garnet, chromite, and ilmenite that may signal the presence of kimberlite pipes containing diamonds.
Heavy mineral analysis involves collecting sediment or soil samples and separating dense mineral grains using gravity concentration techniques. Geologists then examine the mineral assemblages to identify exploration targets and understand geological processes. In addition to exploration applications, some heavy minerals themselves are valuable commodities used in industries such as pigments, ceramics, electronics, and nuclear technology.
The study of heavy minerals provides important information about mineral deposit formation, sediment transport, and source rock characteristics. Consequently, heavy minerals play a critical role in both exploration programs and commercial mining operations worldwide.