It might work to compare pigments, but it is not a trifle - Stefanos Karampelas of Gubelin has a handful of papers on pearl pigments, those would give you a measure of the task. Still easier than controlled culture of such things, methinks.
I will be writing of the other, larger, light green pearls of these shells next (mid-September) alongside a couple of other samples of foliated calcite pearls: at least some of these are not impossible ! Just found a couple.
A.