South Sea Pearls
gold-lip pinctada maxima oyster
by Dr. L. E. Cartier, first published in Facette 23 (February 2017) The South Sea pearl oyster Pinctada maxima is known to produce white, cream and golden pearls. Such pearls are cultured mainly in Australia, Burma (Myanmar), Indonesia and the Philippines. Interestingly, 2016 marked the 60th anni...Colour in cultured pearls has many causes, namely organic pigments and the water reservoir where the pearl shell is grown (sea water or freshwater) that has different manganese (Mn) concentrations with impact on nacre's colours. The mollusc species is, of course, one of the most important factors...Keshi (ケシ), meaning poppy seed in Japanese, was originally used in Japan for very small-sized natural pearls, namely the very rare Akoya natural pearls that were locally collected until the early 20th century. Today, however, the original meaning of the word "keshi" became corrupted and is now a ...