Gleaming faux pearl and smoky topaz vintage necklace signed Japan

I believe that this midcentury necklace is all glass ("pearls", beads and pearly disc), except for metal parts of the clasp. The longest strand is about 28 inches. Marked Japan on the back of the disc. The pinch clasp is secure, and the necklace is in great shape. (There is a small "bump" on one strand, but it's hard to notice and will likely stretch out when the necklace is worn.)