From the studio · Stones, plainly
Akoya pearls, from the cold water up
The short answer: Akoya pearls are grown in cold Japanese and Chinese coastal water over ten to eighteen months. Cold water slows the nacre and that slowness is the entire reason they have the sharp mirror lustre that other pearls do not.
Lustre before size
With pearls, the surface is the whole argument. A 7mm Akoya with knife sharp reflections beats a 9mm pearl that looks chalky, every single time, and costs less. Look at the reflection of a window in the pearl. If the edge is crisp, the pearl is good.
What the grading letters mean
Almost nothing standard. Every seller runs their own AAA scale. Ignore the letters, look at the reflection, and ask for the nacre thickness.
Wearing them
Pearls are a 2.5 on the Mohs scale, softer than almost anything else in a jewelry box. Last thing on, first thing off. Perfume and hairspray dull them permanently.