Sand is a loose fragmented material made up of granules, and gravel is the sand composed of coarse grains. Others precipitate naturally through weathering and erosion, whereby large rocks are gradually reduced in size through natural processes. As a loose granular natural material, sand is normally located in coastal areas, deserts or along riverbank; although it is a composition of mainly quartz and feldspar granules. This is so because its nature can be classified as increased coarseness or abrasiveness of one particle over another on the basis of particle size. Sand is also important in the economy and daily life of people and in the environment; it is used for constructing homes and buildings, for agricultural purposes, and is used in many industries throughout the world; it also serves as home for many different species of animals.