Red rocks owe their colors to the fine hematite and green rocks to chlorite and lack iron oxide. The three major types of sedimentary rocks are mud rocks, sandstones and carbonate rocks. The particles include clay to course silt. These particles are suspended in water and can settle and accumulate only in still waters such as lakes, deltas and lagoons. These accumulate in areas of high energy environments of moving fluids such as rivers and beaches.
Sandstones consist of particles of very fine to very coarse grained sand.
Conglomerates can have particles up to boulders in size. The particles vary in shape from angular to rounded and are poorly sorted to well sorted. The shape of the particle is determined by the amount of abrasion that it encountered. Inorganically formed carbonate rocks are from calcite that has been precipitated. Examples would include areas where an igneous intrusion forces its way through the earth's crust resulting in pressure and temperature changes due to force and friction.