What are some examples of biochemical sedimentary rocks?

When an organism dies, its exoskeleton falls to the sea floor or is deposited by waves and currents, where it eventually gets compacted into sedimentary rock. Biochemical sedimentary rocks are biogenic, meaning that the material for their skeletons or supporting framework was obtained biochemically from the surrounding medium or substrate by specific types of organisms.

The exoskeletons of mollusks, foraminiferans, and reef-forming corals are what form the majority of limestones.

The carbon in buried organic matter and the wood of dead plants that over time petrified instead of decaying due to a lack of oxygen is what forms coal.

Chert is a type of rock that is created when siliceous ooze from radiolarian and diatom skeletons accumulates on the seafloor.

Some examples of biochemical sedimentary rocks include limestone, which is primarily composed of the mineral calcite formed from the accumulation of marine organism shells, and chert, which is formed from the accumulation of silica-rich remains of marine organisms like diatoms and radiolarians. Another example is coal, which forms from the accumulation and compaction of plant remains in swampy environments.