Hi,
It is harder to evaluate pearls that are photographed against a dark background. Please retake the photos against a paper towel or other white background.
Please take a closeup of this pearl. What is that sticking out? (I'm wondering if it is fake pearl coating that has begun to peel off.)
Also, there is something going on between all the circled pearls. Is that just accumulated grime, or is the coating gone (i.e. fake pearls)?
I recommend you give them a bath in some slightly warm distilled water with some mild soap added. Let them soak for about 15 minutes, then wipe them clean with a soft cloth. If it's just grime it should come off.
Then re-photograph them against a white background.
I can't read the marks on the clasp. Can you take a better closeup? Or just tell us what the clasps read.
Edit: I have to add that they are giving a strong vibe of fake pearls. But try cleaning them as I suggested.