This shell, also called the Rainbow-Lip Oyster, can produce pearls up to 12mm of diameter with an amazing range of colours, from blue to violet, green, pink or purple. and the shape can vary from baroque to drop, oval or round. The exterior of the shell is purplish-brown to yellow, while the inside is pearly and variable in colour. The shell is moderately thin, has lines sculpted on the surface, and can attain a length of 9 cm. Pteria Sterna stay attached to living and non-living hard substrates at depths of 1-5 meters, in subtropical to warm temperate waters, mostly in the Gulf of California area.