“A” writes:
Sedimentary rocks are made from tiny particles of rocks and sand ,or tiny pieces of shells, plants or animal remains, which form layers and eventually become rock.
Here are some websites that give more information:
http://fi.edu/fellows/fellow1/oct98/create/sediment.htm
http://www.windows.ucar.edu/tour/link=/earth/geology/sed_intro.html&edu=elem
Limestone is a sedimentary rock. It is formed from tiny shells and micro-skeletons.
Below is a picture of sandstone.
It is made of sand particles.
In the Natural History Museum we found a stone named the Sunday stone. It was a sedimentary rock. It was made in a coalmine so the black lines are work days and the white lines are days off:
