I think they may actually be cultured akoya pearls that were restrung in a way that one would usually use for lesser bead necklaces. It's hard to tell luster against a dark background-- white paper towel would be better. Also if they are grimy from all the usual stuff (skin oils, cosmetics/lotions, air pollution) the luster won't show well. I suggest you wipe them with a soft, damp microfiber cloth and photograph them again.
If you think you'd like to wear them, we have a tutorial on how to do that. It's not hard. Old silk becomes weakened, and restringing is a good idea to prevent losing them.
After wiping them, do this simple test: rub 2 of them together gently. What do you feel? Real pearls are gritty feeling; fake pearls glide smoothly.
Not sure what is gong on with that center pearl. Looks like a fake that has lost its coating. I wonder if the last stringer combined real and fake pearls?