As a seller said to me after I purchased a beautiful set of two Joseph Rodgers 5/8's (above your set), I emailed him and asked him if the scales were made of bone or horn? He emailed me back, and with a wink said, "they are made of the other kind of material that looks like bone", they were in fact Ivory - wow! And the scales on that set are undoubtedly Ivory, they are antique's, and beautiful. Enjoy them!