I have recently began collecting cameos. It seems as though may of the female subjects reappear on cameo jewelry. Is this due to other artists reproducing previous works? Does this mean that they are less valuable even if they are still shell cameos? I know the infamous "girl with ponytail" is a recent creation and is generally associated with modern resin cameos. But aside from this are there other women subjects that reappear frequently, aside from famous or religious figures. Thanks for your insight!