cblebrun,
Welcome! Yes, cultured freshwater pearls from China, and possibly pretty red garnet beads, too! Many imitation pearls are knotted to make them look more "real." And as DK mentioned, genuine cultured pearls are not always knotted, either. Your pearls are all nacre; they didn't form over a bead, which is why they are more egg shape than round. I hope you will enjoy your pretty necklace.