What kind of sedimentary rock is made from the remains of plants and animals?

Sedimentary rocks are classified based on their mode of formation, and organic sedimentary rocks are specifically formed from the accumulation of plant and animal remains. These organic materials, which can include things like coal from plant matter and limestone from shells and skeletons of marine organisms, become compacted over time, eventually hardening into rock. This distinguishes organic sedimentary rocks from other types, such as clastic rocks, which are made from pre-existing rock fragments, and chemical rocks, which form from mineral precipitation. Igneous and metamorphic rocks represent entirely different geological processes involving molten material and the alteration of existing rocks under pressure and temperature, respectively. Thus, the recognition that organic sedimentary rocks derive directly from biological material is key to understanding this category of rock.