Sand
Sand comes from rocks 
that have been broken up by weathering. Some rocks are broken down into sand right in the desert. Other sand grains are picked up by the wind and carried hundreds of miles to the desert.
Hot days and cool nights make rocks expand and contract. Natural cracks in bedrock gradually widen until pieces begin to break off. Large blocks are broken down into smaller and smaller pieces.
Grains of sand in deserts become rounded and frosted over time. They have been sandblasted. The orange colour comes from staining. Under the stain, the grains of sand might be white or clear.
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