hiekkä

Hiekkä is the Finnish term for sand, a granular material composed of finely divided rock and mineral particles. Sand is defined by particle sizes roughly between 0.063 and 2 millimeters in diameter and by properties that distinguish it from silt, clay, and gravel. The most common constituent of sand is silica in the form of quartz, though the chemical and mineral composition varies by source; some sands contain feldspars, micas, or heavy minerals.

Sand forms by the weathering and erosion of rocks, followed by transport and deposition by wind, water, or ice. Sorting and rounding during transport produce distinct sand types: well-rounded, well-sorted beach sands; angular, poorly sorted dune or inland sands; and river sands with a wide range of grain sizes. Sand deposits occur on beaches, deserts, river valleys, and in petroleum reservoirs.

Common uses include construction (sand as a component of concrete and mortar), glassmaking when high-purity silica is available, and filtration in water treatment. Sand is also important in agriculture as a soil texture component and in recreational contexts such as beaches and playgrounds. Environmental considerations include habitat impacts of dune and beach mining, groundwater movement, and the health risk of inhaling crystalline silica dust to workers.

In Finnish language and culture, hiekkä is the general term for this material and appears in everyday speech as well as in geographic names and descriptions of landscapes involving sandy soils or shores.