There are three different types of sedimentary rocks.

• Clastic sedimentary rocks: Formed from clasts or pieces of other rock. (Eg: sandstone)
• Organic sedimentary rocks: Formed from hard, biological materials like plants, shells, and bones that are compressed into rock. (Eg: coal)
• Chemical sedimentary rocks: Formed from chemical precipitation. (Eg: limestone, halite, and flint)

Further Reading:

• The Rock Cycle
• Geography Notes