Figure 13. Akoya Pearls
Pearls are created when an irritant – natural or man made – enters the shell of a mollusk. The animal covers the parasite in coatings of calcium carbonate to decrease its irritation level to its body (Murr & Ramirez, 2012). The calcium carbonate is made of aragonite and conchiolin and is micro-layered hundreds or thousands of times to create the nacre. Naturally occurring pearls are caused by invasion of marine worms or tiny rocks (Southwell, 1924). Pearl farmers artificially place a bead into the oyster and track the progress until the pearl reaches the desired size. This process can take anywhere from six months to four years (Winterson, 2023). The East Asia region hosts a number of these farms.
Japan and China are the sources of the world’s highest quality pearls. China supplies freshwater pearls while Japan is known for their Akoya pearls (Shor, 2007). Particularly, the Mie region in Japan has a unique coastline and ecosystem that is favorable to the nacre quality. The mountainous coastline is spotted with coves that support a vibrant plankton population which feeds the pearl creating mollusks (Haruyama, 2010). The water is colder than most other pearl regions causing a finer finish and denser nacre in the finished product (Muhammad, 2017). These elements are important because they cause the highest chance of an Akoya pearl – perfectly symmetrically round.
