Final answer:
Calcium carbonate is the most commonly precipitated solid by water-dwelling organisms for building shells and skeletons, contributing to biochemical sedimentation and the formation of rocks like limestone.
Step-by-step explanation:
The solids most commonly precipitated by water-dwelling organisms to build their shells and skeletons include calcium carbonate (CaCO3), silica (SiO2), calcium phosphate (Ca3(PO4)2), and calcium sulfate (CaSO4). Among these, calcium carbonate is predominant. Organisms like mollusks and corals use calcium carbonate to make their shells, which contributes to the formation of sedimentary rocks like limestone. These biologically created structures are part of what is known as the biochemical sedimentation process. Additionally, silica is used by organisms such as some algae and sponges, while calcium phosphate is a principal component of vertebrate bones and teeth.