Does "Japanese grey akoya pearl"="Madama"?
I'm not sure how to distinguish grey akoya pearl & Madama. Does madama can be dyed? Or they must be natural color? A dealer said the deep strand is grey pearl, light-color strand is madama. Is she right?
Bweaves is right. Madama is the highest grade of natural color blue akoya pearls. I haven't heard that it encompasses gray. The key is to purchase pearls that make you happy and not worry about terms. Whether you are getting value for the price is something to be concerned about.
Agreed! Madama isn't differentiated by light vs dark, it's a quality designation like hanadama and is very rare and difficult to source. It's basically the opposite of a dyed gray akoya strand - high quality (dyed are universally lower grade) and natural color.
Madama Akoya pearls must not be dyed and have certificate from Pearl Science Laboratory Japan. The pearls in your photos look irradiated Akoya pearl, unfortunately. They are not natural blue colour but irradiated by gamma rays.