seasand

Seasand is a generic term for sand reclaimed from marine or coastal environments. It is commonly found on beaches and in nearshore deposits. Grain size ranges from fine to coarse, and the material is often dominated by quartz, with calcium carbonate from shell fragments and minor amounts of feldspars and biogenic grains. Because seasand originates in a saltwater setting, it often contains residual salt and moisture, which can affect handling and its suitability for certain applications.

Seasand forms through wave action that erodes rocks, transports particles, and deposits them in shallow marine zones. Source and processing determine its properties, including salinity, grain-size distribution, and mineral content, which vary regionally.

Uses include construction, filtration, and landscaping, but suitability depends on desalination and impurity content. In construction, sea sand may be used for non-reinforced concrete or plaster after desalination; in reinforced concrete, chloride-containing sands are typically avoided due to corrosion risk. In filtration, silica-rich seasand can serve as a media for particle removal. In horticulture and drainage, washed seasand provides drainage and soil structure, though high salinity can harm plants unless treated.

Environmental and regulatory considerations are important. Coastal sediment extraction can affect habitats, erosion, and sediment transport; many jurisdictions regulate dredging and require impact assessments and treatment to reduce salinity and contaminants.

Related topics include beach nourishment, silica sand, and sand mining.