A number of the pearls have eggy shapes; this is typical of cultured freshwater pearls from China. Being all nacre they have no bead inside to make them round. These kinds of pearls have been around since the late 1990s/early 2000s or so.
They are a nice size and length, and the surface seems good. The gold clasp adds some value, but being off-round freshwaters, they are not a particularly valuable strand of pearls. But being all nacre they are really durable.
They will look much better if you give them a bath and restring them. The thread has become very grimy with use, which also weakens it.
You can give them a bath for 15 minutes or so in a solution of mild soap and distilled water (to avoid both chlorine and hard water minerals), then use a soft cloth, brush or swabs to wipe away grime. Rinse in more distilled water and lay them on a towel to dry for 24 hours.
I suggest you restring them yourself! It saves money and is a great skill to have. Then you can shorten the necklace if you wish, or remove any pearls that are not as good as the others. For that matter you can add other beads, spacers etc. to create a different look! Many of us restring our pearls -- it isn't hard and saves money. If that interests you, have a look at my stringing tutorial:
How to string (or restring) your pearls on doubled Pattye's Serafil, Beaders Secret, and Power Pro
This is not hard-- really! It is harder to describe it than to do it. Anyone can learn to string their own pearls!
If after reading through this, it sounds too daunting, I suggest making a mini-strand for practice first. Make one 12-15 pearls long just so you can practice how to knot the end 3 pearls on each side and attach the clasps; the middle pearls are easy to knot.
To just practice knotting (without bothering with clasps), make an overhand knot, string on a pearl (or...