How do clastic sedimentary rocks differ from organic and chemical sedimentary rocks?

Clastic form from the deposition of eroded particles of rock. These particles or "clasts" are lain horizontally once the transporting agent's energy is expended. They are then consolidated into layers or "beds" of rocks through compaction or through cementing. Chemical or non-clastic sedimentary rocks form through chemical precipitation. This is when the concentration of minerals in solution exceeds a certain level. Organic deposits are products of biological activity and the remains are deposited and consolidated into rock.