Not the best pictures for identification, but let's start with what I can see.
They are off-round, not half round. The gold are rollers and the blacks are both rollers and spinners, terms that come from how they behave on an inclined glass surface.
They all appear to have nuclei, so likely cultured pearls (as opposed to faux).
I'm hesitant to suggest either Tahitian or South Sea for a few reasons. Although the circles around the holes of the black ones are white, they give a first impression of being dyed freshwater pearls, or at the very least lower quality than the dazzling peacock hues we normally see in pearls from the atolls.
The gold ones appear to have gold rings around the drill holes and are just too dark and uniform to be authentic SS pearls, lest they'd be every expensive.
I'd need to examine these much closer to be certain, because otherwise that's just my best guess.