Hard Facts about Sand

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The word sand conjures images of soft, silky beaches in exotic locations. We think of sand as being white or golden and children are taught to colour it yellow. Sand, to most of us, is a material created for our pleasure.

FACT 1: Sand is actually particles of minerals, rock or soil. The particles are between 0.02 and 2 millimetres in diameter. Most of the minerals that form the rocks on the earth’s surface are found in sand. Minerals commonly found in sand include quartz, feldspar, iron ores, volcanic glass, calcareous material and iron ores.

FACT 2: Quartz is the most common constituent of sand. Quartz is found abundantly in rocks on the earth’s surface. It is a hard mineral and resists erosion. It does not decompose easily and is practically insoluble in water. Sands that have quartz as the dominant constituent also contain feldspar and small quantities of white mica. White mica is soft, but decomposes slowly.

FACT 3: Small quantities of heavy rock forming minerals are always found in sand. These minerals include garnet, topaz and zircon. As river and shore currents wash away the lighter constituents these minerals become concentrated in the sand. These sands can be worked to extract diamonds, gemstones, gold platinum, tin and other ores.

FACT 4: On the floor of the oceans greensands are commonly found. These sands contain glauconite which gives them the greenish colour. Glauconite contains potash and so these sands are used for water softening.

FACT 5: Sand is used in many human activities. Very pure quartzose sand is used as a source of silica in glass and pottery making. This kind of sand is also used to line the hearths of acid-steel furnaces. The moulds used in cast metal foundries are made of sand containing clay. Some special sands are used as abrasives and ordinary sands are used for making mortar, cement and concrete.

FACT 6: Many beaches around the world have black sand. This is caused by the erosion of volcanic rock. Many beaches in Hawaii have black sand. Some beaches have both white and black

FACT 7: White sand beaches have a high concentration of quartz. In Hawaii there is no source of quartz to make the white sands. The white sands of Hawaii are composed of the carbonate shells and skeletons of marine organisms like corals, molluscs and algae. These organisms live in reefs or in shallow marine waters. The reefs are constantly being broken down into sand by bio and mechanical erosion. Bio erosion of the reefs is caused by grazing fish and sea urchins, bivalves and boring worms and sponges. The mechanical erosion is caused by the action of the waves.

FACT 8: In beaches on the western coast of India, the white sand is often streaked with black. These black bands are actually composed of tar balls created by the action of water on minor oil spills. Ships taking oil from Mumbai to the Southern parts of India On the return journey the tanks are cleaned by spraying boiling sea water. The residual oil in the tanks washes into the sea and is carried by the tides to the beaches. Cleaning of oil tanks in the ocean is against the law, but is still widely practised.

FACT 9: Strangely enough sand can be considered an endangered species. Human activity interferes with the processes that make sand. In most parts of the world buildings and resorts are built along the shore line. Sand is being indiscriminately harvested for construction activity. Many of the famous beaches of the world are now artificial. The beaches are replenished by sand imported from others areas. The sand for replenishing Waikiki beach Hawaii was brought from neighbouring islands and from as far away as the West Coast of USA.

FACT 10: Sand is one of the most valuable materials on Earth. Without sand there would be no buildings, glass, electronic chips or ceramics. Sand powers the development engine. It must be treasured and used carefully.

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