Sand

Sand [[dune Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of soil or soil type; i.e., a soil containing more than 85 percent sand-sized particles by mass.

The composition of sand varies, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal settings is silica (silicon dioxide, or SiO2), usually in the form of quartz.

Calcium carbonate is the second most common type of sand, for example, aragonite, which has mostly been created, over the past 500million years, by various forms of life, like coral and shellfish. For example, it is the primary form of sand apparent in areas where reefs have dominated the ecosystem for millions of years, as in the Caribbean. Somewhat more rarely, sand may be composed of calcium sulfate, such as gypsum and selenite, as is found in places such as White Sands National Park and Salt Plains National Wildlife Refuge in the U.S.

Sand is a non-renewable resource over human timescales, and sand suitable for making concrete is in high demand. Desert sand, although plentiful, is not suitable for concrete. Fifty billion tons of beach sand and fossil sand are used each year for construction. Provided by Wikipedia

Search Results

Showing 581 - 600 results of 846 for search 'Sand', query time: 0.15s Refine Results
  1. 581
  2. 582
  3. 583
  4. 584
  5. 585
  6. 586
  7. 587
  8. 588
  9. 589
  10. 590
  11. 591
  12. 592
  13. 593
  14. 594
  15. 595
  16. 596
  17. 597
  18. 598
  19. 599
  20. 600
Search Tools: Get RSS Feed