The first type is called conglomerate . Conglomerates are made of pebbles or larger rocks cemented together. The second type is called sandstone . Sandstone is composed of sand grains which are cemented together. Shale is the third type of sedimentary rock.
Shale is clay that has been converted into rock masses.
The next group is called limestone . Limestone is generally composed of calcium carbonate, microscope shells, or both. The final group of sedimentary rocks is called gypsum or common salt or Epsom salt. These are compounds found in sea water that precipitate as the water evaporates. Sedimentary rocks are usually formed in several layers called strata .