Abstract
There is an argument for the calcium carbonate phase constituting larval shells of mollusks, especially the existence of amorphous calcium carbonate (ACC), is under discussion. In this study, we have investigated the larval shell of Pinctada fucata, using various analytical techniques to solve this problem. From TEM observation of the specimen made by FIB, the larval shell consists of three layers all of which are made of aragonite and ACC was not found. However, this result may be an artifact due to heating during FIB preparation. Hence, we analyzed the shell using XRD, and FT-IR, and Raman spectrometry. XRD and Raman spectrometry showed no sign for the existence of ACC. Only FT-IR spectra contained the peak, assignable to ACC.
