Yes a curious piece. Proveneance at face value, the pearls certainly would be natural. They do look natural at first glance merely by size.
Very random in selection criteria although strict in the measure for uniformity to one another in size.
They've been drilled so that very often means destroyed in science, thus more difficult to be conclusive in a lab, though it's still doable.
The light isn't ideal, but the nuclear materials seem somewhat uniform with marked distinctions at a rate of about 7:3. That's a bit high to be comfortable. Even 5:5 isn't great. In other words, skeptical. More from caution than suspicion.
I am impressed by the centerpieces. They seem to be assembled from cut stone or glass. If folk art, this is more creative and thoughtful than costume pieces by far. Like I say, I'm really curious about the history of this piece.