It looks a bit like an "add a pearl" necklace. I remember those from when I was little (decades ago). You were given a gold chain with one pearl, and then every year someone would buy another pear to slip onto the chain. The idea was that you would have a full pearl necklace by the time you were an adult. How anyone ever got a matched necklace I'll never know.
Are there knots between the pearls, or do they slide on the chain?
Also, this necklace won't be worth very much, I'm afraid.