Abalone pearl?

[vroom]

OK Caltiin as promise here is where I show my naivet? - is this a abalone pearl or just a bit of polished shell? It is from my wife's collection and her grandmother gave it to her many a year ago. Other than this I just have a few loose pearls here and there. Of course who knows what might be hiding in a corner of lock box somewhere or what I might find tomorrow LOL.

But I am working on that connoisseurship title.

 

[Lagoon Island Pearls]

Abalone typically have horn shaped pearls, but this one appears to be a piece of cut shell. The nacreous surface is narrow and concaved while the prismatic structure appears in layers. If this were a natural pearl, the nacre would surround the pearl, obscuring the prismatic layers and an amount of conchiolin would be present on the opposite side.