quartzose

Quartzose is a descriptive term used in geology and soil science for rocks, sediments, and soils in which quartz is the dominant mineral. It is most often applied to sands and sandstones but can describe any granular material with a high quartz content. The term reflects a composition that is largely free of other silicate minerals such as feldspar or lithic fragments.

In mineralogical and textural terms, quartzose materials contain abundant quartz grains, with only small amounts of accessory minerals. In sands, quartzose varieties are typically well sorted and quartz grains can be well rounded due to sustained transport; when present, cementing agents are usually silica or carbonate. The high purity of quartz often leads to distinctive physical properties, including high resistance to weathering and variable porosity depending on cementation and grain contacts.

Formation and occurrence of quartzose materials are commonly linked to prolonged weathering and transport from quartz-rich source rocks, such as granites, granitic gneisses, or quartzites. They are prevalent in mature sedimentary environments, particularly beaches and dunes, river or desert settings, and in regions with bedrock that yields abundant quartz.

Examples and significance: The term is frequently encountered in sedimentology and petrography, with quartz arenites and quartz-rich sandstones illustrating highly quartzose compositions. Such materials are typically used to describe reservoirs and aquifers in petroleum geology and hydrogeology, where high quartz content can influence porosity and permeability. See also quartz arenite, quartzite, and sandstone.