What are organic sedimentary rocks?
Sedimentary rocks are classified by what kind of sediments they have. Clastic sedimentary rocks are made from rock and mineral fragments that are compressed and cemented together to make a rock. These sediments vary in size and may be gravel, sand, silt, or clay. Chemical sedimentary rocks precipitate from a fluid. Organic sedimentary rocks, such as limestone and coal are made from the bodies of plants and/or animals.