That 9th pearl in from the tongue of the clasp is very oddball, doesn't match the strand as a whole, but it's exceptionally silvery and iridescent, due to the nacre being very convoluted (and therefore thick)-- except there is one part right near the drill hole where either there is no nacre, or the nacre is just not iridescent. It looks like porcelain, a bit translucent.
I thought about restringing and omitting this one pearl, but the strand looks fine with it, especially as it's back nearer the clasp. And I don't want a shorter necklace.
Edited: I examined it again with a loupe; I'm seeing fine cracks that reach the surface and have begun to be worried that it may someday break apart and the pearl will be lost at some point in the future, from stress near the drill hole.
So...I've contacted Jeremy to ask if there is a spare pearl to replace it with, if and when I need to do so.
Edit: And updated again to add that I've decided to leave well enough alone for now. If it ever cracks, I can always substitute a round pearl instead, if no spare baroque has been found by then.