I have a necklace EXACTLY like yours. It's Mikimoto's Blue Lagoon brand, which is where the "BL" comes from. It's one of Mikimoto's several lower cost, lower quality pearl lines. However, even Mikimoto's lower quality pearls are still excellent quality.
The clasp and the bead end caps are original to the necklace. It's one of the few times I can tell someone that the clasp is actually from the brand that made the necklace. The clasp is 14K gold. The pearls are in the 6-6.5 mm range, so on the smaller size for akoya pearls these days.
I even found the original appraisal document in my Mom's jewelry file. The pearls belonged to my Aunt Love.
There's no way these cost $1500. That was probably the price for insurance purposes. I think they were more in the $500-$600 range when new, but I'm guessing. Oh look, the appraisal is 1998, so almost 20 years old, just like yours.
Somebody, a year ago, was asking about Sakura pearls, and there was no info on the internet about them. And lo and behold, here's Sakura pearls mentioned. I think the appraisal form covered every brand of pearl that Best company sold. My Aunt Love's pearls were definitely Blue Lagoon, because they still had the Blue Lagoon tag hanging off them. She had never worn them.
Moral of the story: You have a really lovely strand of pearls. Give them a gentle wash, as mentioned previously, wrap them loosely in a towel. When the towel is dry, the pearls will be dry, too. Your knots look pretty good and clean, so you may not need to restring yet. Wear them and enjoy them. They're good quality.
