Pearl and stone necklace

This necklace was acquired at an estate sale and I cannot give you the exact origin and it seems to have no designer marks. The stone beads are mauve, chocolate beige and gray. If you think you know what the stone is, please comment. The real oblong freshwater pearls are knotted in between. It's not heavy as you might think. Its listed for people looking for the one of a piece kinds of jewelry.