Microarchitecture and deposition of gastropod nacre.

The microarchitecture of gastropod nacre reveals deposition of aragonite in the form of crystal stacks and differs markedly from the characteristic microstructure of pelecypod nacre. The structure permits direct observation of both organic and mineral phases of deposition on a growth surface topography that is ideal for the study of processes of mollusk shell calcification. The stack mode of deposition is functionally useful to the animal because it increases the number of crystals which can form and develop on the growth surface at one time.