No, shells are biomaterial, not rocks.
shells
shells are compacted with the layers of sediment, making it, actually, a part of the rock
carbonaceous shells form limestone which in this case is a bio-chemical sedimentary rock
Coquina is an organic sedimentary rock composed primarily of cemented shells of marine organisms.
yes
Limestone made from shells would be an organic sedimentary rock.
Fossils are made of rock, which has replaced the original material.
oyster shells
Limestone
chalk
A Sedimentary Rock. Eg, Bioclastic Limestone.
A sedimentary rock called coquina.