Just beautiful and not perfectly matched! Are you sure the marks are not HW for Harry Winston being that they came in a Harry Winston Box and all, and being that they were acquired in New York? Harry Winston (March 1, 1896 – December 28, 1978) is one of the most famous jewelers and diamond merchants in the world! He donated the Hope Diamond to the Smithsonian Institution in 1958 after owning it for ten years. Check the marks again - they are not clear.
....whatever they are beautiful black pearls! Farah