Hi,
Sorry for the delay in approving and merging your threads-- I just got up!
To me they look like imitation pearls. Here is why:
The pearls all look identical in size and shape, except for the end pearls, which are considerably smaller than the rest-- and I've only ever seen that done with imitation strands. Also notice there is no knot between the end pearl and the larger one next to it.
There are no overtone colors such as one would expect to see with cultured pearls.
In genuine pearl strands there are usually some flaws; I don't see any on this strand.
The clasp is attached with inexpensive findings.
The clasp itself looks like an imitation gold-tone clasp with a glued-on pearl (I have seen clasps like this on imitation strands before.)
The knots are rather large, which is because the drill holes of imitation pearls tend to be larger than those of genuine pearls. Pearls are sold by weight, and with real pearls the holes are made small to preserve weight.
If you are not sure about this assessment, try gently rubbing one pearl against another. Imitation pearls will glide smoothly on one another, whereas genuine pearl nacre offers a little bit of resistance or grittiness.
If you examine the pearls closely it is possible you may find areas where the coating has flaked away. Imitation coating tends to be think and flaky. Underneath you may see the glass bead.
Look for a metal mark (14K, 585) on the clasp. Imitation pearls are not usually strung with gold clasps. High end imitations like Majorica are strung with vermeil or sterling silver, however, and are stamped 925. But these do not look like Majorica.
Some but not all imitation pearls have beveled drill holes.
Edit:
Now that I've seen your most recent thread, I can tell you definitively that they are imitation. There are assorted companies that make imitation pearls with similar names. Majorica is the original high end one but there are also imitators: Majorca, Mallorca, and now I see your Mayorca. (Which is a bit funny when you think of it-- imitations of imitations....)
That said, there is no reason not to enjoy them and wear them, especially as they may be sentimental to you, having been owned by your grandmother. I own a number of Majorica strands myself, including one that used to be my mother's.
Many prominent women wore imitation pearls. Coco Chanel did, Kate Middleton wears imitation drop pearl earrings, and Jackie Kennedy's famous pearls as well as Barbara Bush's huge pearls were fakes made by Kenneth Jay Lane. Brooke Astor sometimes wore imitations too.