One or several mother-of-pearl cores are inserted into the saltwater mussel – together with a piece of mantle tissue of a strong and healthy donor mussel. The cells in this piece of tissue have the ability to produce mother-of-pearl. After several weeks of intense care, the mussels are placed in wire baskets and hung from rafts in the sea. The mussels and water must be checked periodically. The quality of a saltwater pearl depends not least on the nature of the core. Its shape and surface directly influences that of the resulting pearls. The growth period for the Akoya pearl is at least 10 to 14 months, but usually 18 to 24 months.