Ok so I tried the first test mentioned, the rub together test, but the pearls are quite small so it was really hard to tell if they were smooth or if they were slightly gritty.
I then tried the rub on my tooth method. Again, hard to tell. I think I need to make a friend locally who has an x-ray machine or something...
For now though, they will be faux pearls until I can figure out for sure.
One bag is labeled cultured but everything else will have to be a mystery!