The original Japanese cultured pearls are produced by a species of small oysters no bigger than 6 to 7 cm in size, hence Japanese pearls larger than 10 mm in diameter are extremely rare and highly priced.
Noocyada asaliga ah ee dhaqanka Japan ee loo yaqaan 'akoya pearls' waxaa loo yaqaan 'pearada pearl', Pinctada fucata martensii, taas oo aan ka weynayn 6 si 8 cm xajmiga, sidaas darteed akoya pearl ka weyn 10 mm dhexroor waa dhif iyo naadir qiimo badan.