Are all nucleating beads round? Well, let me be more specific, because I know some beads are shaped to obtain things like stars, and coins. Are any of the nucleating beads deliberately egg- and oblong-shaped?
The reason I ask is because I'm backlighting all of my pearls, and I see oblongs and eggs inside - no round-beads in my non-round pearls. In my more round pearls I see round beads.
There are distinct halos visible surrounding obviously solid, discernible shapes at the center of the pearls.
So, why is this what I'm seeing? Is it an artifact of the density of the aragonite-conchiolin as it's unevenly layered around a round bead? or what?