Classification is precisely outlined in the "Official Journal" of French Polynesia. To that day there is no teaching available, thus it belongs to each
jewelry store to evaluate and grade their pearls.
Most use this classification. As prices depends on this
grading, the same
pearl could be expertised differently from one store to the other
upon retailer's knowledge, expertise and professional ethics
! The local authorities do not operate any control.
You should be patient, looking, asking, curious in order to find
your pearl at the fair price, because most of the time, very
high pricing is not a high quality guarantee !