A granular material that is composed of finely divided rock and mineral particles is called as Sand. This loose granular material blanketing the beaches, riverbeds and deserts of the world is composed of different materials that vary depending on location.
Silicon dioxide in the form of quartz is the most common component of sand. The landmasses of Earth are made up of rocks and minerals, including quartz, feldspar and mica. Processes of weather such as rain, wind and freezing/thawing cycles break down these rocks and minerals into smaller grains. It is formed when the reef breaks down, either by mechanical forces such as waves and currents or from bio-erosion caused by grazing fish, urchins and other marine life.
Types of Sand:
- Sand comes in many different colors including white, black, green and even pink.
- Quartz is hard, insoluble in water and doesn't decompose easily from the weathering processes. Rivers, streams, and wind transport quartz particles to the seashore, where the quartz accumulates as light-colored beach sand. Continental sand is usually composed of quartz. It also contains bits of feldspar and other rock fragments.
- Tropical islands, like the Hawaiian Islands do not have a rich source of quartz. So the sand is different in those locations. The beach sand of tropical islands looks white because it is made up of calcium carbonate. It comes from the shells and skeletons of reef-living marine organisms, including mollusks, corals and microorganisms called foraminifera.
- Bermuda is famous for its pink sand which is composed of eroded calcium carbonate. The ruddy hue of the sand is from the abundant red foraminifera, Homotrema rubrum.
- Sometimes, the mineral olivine are separated from other volcanic fragments by erosive forces. This lead to green sand beaches, such as Hawaii's Papakolea Beach.
From sediments transported into the ocean and the erosion of ocean rocks, marine sand or ocean sand are created. The thickness of the sand layer varies. However, it is very common to have more sand closer to land. This type of sand is ideal for construction. Beach sand is also formed by erosion. Rocks are eroded near the shoreline from the constant motion of waves and the sediments build up over thousands of years. The process of creating a beach, along with marine animals interacting with rocks, such as eating the algae off of them are accelerated by weathering and river deposition. The beach acts as a barrier to keep the land from eroding any further once there is a sufficient amount of sand. As it is angular and of various sizes, this sand is ideal for construction.
Tropical beaches may also contain black sand, which is composed of black volcanic glass. Sand dunes are a consequence of dry conditions or wind deposition. Because of its geographic location, the Sahara Desert is very dry and is known for its vast sand dunes. They exist here because very little vegetation is able to grow and there's not a lot of water. Over time, wind blows away all the fine particles, such as clay and dead organic matter, leaving only sand and larger rocks. The wind is responsible for creating these different environments and shaping the sand to be round and smooth which make desert sand unusable for construction. Sand from rivers are collected either from the river itself or its flood plain. These are the majority of the sand used in the construction industry.
Uses of Sand:
Sandy soils are very good for crops such as peaches, watermelons, and peanuts. Their excellent drainage property make them suitable for intensive dairy farming.
Sand can be added to a mixture of clay and other materials for manufacturing bricks.
Sand is a principal component of critical construction material.
In common glasses, sand that is rich in silica is the principal component.
When sand is mixed with paint, it produces a textured finish for walls and ceilings or non-slip floor surfaces.
It is used by media filters for filtering water.
These protect against floods and gunfire. These inexpensive bags are easy to transport when empty, and unskilled volunteers can quickly fill them with local sand in emergencies.
Sand is used by engine drivers and rail transit operators to improve the traction of wheels on the rails.