1. Clastic sedimentary rocks: These rocks are formed from the fragments of pre-existing rocks, minerals, or organic matter. Clastic sedimentary rocks are classified based on the size of the fragments that make them up. Some common types of clastic sedimentary rocks include sandstone, mudstone, and conglomerate.

2. Chemical sedimentary rocks: These rocks are formed by the precipitation of chemicals from solution. Chemical sedimentary rocks are classified based on the chemical composition of the minerals that make them up. Some common types of chemical sedimentary rocks include limestone, dolomite, and evaporites (such as gypsum and halite).

3. Organic sedimentary rocks: These rocks are formed from the remains of plants and animals. Organic sedimentary rocks are classified based on the type of organisms that they are formed from. Some common types of organic sedimentary rocks include coal, oil shale, and limestone.