How sand is formed in the earth

When the solid rock is exposed to the action of wind, rain, and frost, and broken up into smaller particles, if the particles are small enough

(Between one five-hundredth of an inch in diameter and one-tenth of an inch in diameter), these particles are called sand.

Sand is formed of small grains of the minerals that make up the rocks. Hence these minerals may be found in sand. The main mineral found

found in sand is quartz which is very hard and is quite abundant. Sometimes as much as 99 per cent pure quartz may also be found. Other

minerals sometimes found in sand are feldspar, calcite, mica, iron ores, and small amounts of garnet, tourmaline, and topaz.

Where sand is found: Sand is found wherever rocks have been exposed to the weather. One of the principal sand-forming regions is the beach of

a sea. There the action of the tide upon the rocks, the action of wind-blown sand rubbing against the rocks, and the dissolving of some of the minerals

in the rocks by the salt water, all combine to make sand.

Sand in desert: Most of the loose sand in deserts has been brought to this place by wind. In some cases, the desert sands may have

been formed by the decay of rocks. In still other cases, the desert was once really a sea bottom and the water retreated thousands of years ago, leaving

the sand. Sand is a very useful substance. It is used in making concrete, in making glass, sandpaper, and a filter in helping to keep water pure.