What is it and where is it formed?  Gravel is made up of small rocks.  It can be a mixture of sand, clay, and small pieces of rock.  It is sedimentary rock and usually found where there is, or were, rivers, lakes, and glaciers.   It happens where rocks have been weathered by wind or water or eroded. 

How and where is it mined?  Gravel is mined using open pit mining or quarrying.  It is dug up, washed, and then sorted by size.  It is mined in all states but the most comes from California, Texas, Michigan, Ohio, and Arizona.  It also comes from Belgium, Brazil, and Australia.

What is it used for?  Gravel is used to make glass, concrete, and in road building.  It is one of the cheapest rocks that is mined but it is needed all over the world.