Pearl oysters of the species Pinctada maxima (silver lip or gold lip pearl oyster), P. margaritifera (black lip pearl oyster), and Pteria penguin (bat wing pearl oyster), are all used in the Australian cultured pearl industry, but Pinctada maxima is by far the most important economically. Pinctada fucata is of very little commercial interest in Australia but was included in this study for comparative reasons.

While this project was specifically the study of the "electronmicroscopy of tissues which produce pearl shell organix matrix" it is part of a much larger study of these tissues, their secretions and the shell parts formed by their secretions. Also it is an extension of several previous years' work on the light microscopy of decalcified pearl shells and the tissues of the External Mantle and Mantle Margins which produce them.