<p><span style="font-size: 13.008px;"><strong>Fig. 3.64.</strong> Layers of nacre inside a black-lip pearl oyster (<em>Pinctada margaritifera</em>) shell with all living tissue removed. A pearl is small particle lodged between the mantle and shell that becomes covered in a nacreous layer.</span></p>

Fig. 3.64. Layers of nacre inside a black-lip pearl oyster (Pinctada margaritifera) shell with all living tissue removed. A pearl is small particle lodged between the mantle and shell that becomes covered in a nacreous layer.

Image courtesy of Didier Descouens, Muséum de Toulouse