Akoya cultured pearls are the most common cultured pearls.
They are typically between two and nine millimetres in diameter; examples which are larger than nine millimetres are rare, and the maximum size is 11 millimetres.
The main areas of production are the coastal regions of China and central and southern Japan.
Their colour ranges from pink, rose-tinted white, cream and green/white, to champagne and natural silver grey. Artificially coloured black and dark grey examples are also available.
The Akoya pearl oyster, Pinctada fucata martensii, only reaches between seven and ten millimetres in size and produces a nacre layer between 0.6 and one millimetre in thickness each year. Cultivation of a pearl takes between six months and two years.