Pearl Necklace -Long String of Graduated Pearls 28”

Vintage graduated pearl necklace. I don’t know anything about the origin of the necklace or authenticity of the pearls. There are no hallmarks on the gold color clasp. There is some weight to them, they are graduated in size, with the center pearl being the largest at approx. 8mm & the pearls close to the clasp approx 3mm in diameter. Overall length is 28”