I have a pearl choker necklace. The clasp was made for a double strand necklace, but there is only one strand now and I don't think the pearls in this strand are original to the necklace. The clasp itself is beautifully made, with 18k gold and very white pearls. This necklace came down in my family and my guess is that it is 120 to 150 years old. I would love an opinion on this.