[header] How to tell if a cameo is authentic [title] Know which materials are most authentic. [step] Authentic carved cameos can be made of shell or natural stone, while authentic painted cameos are typically made from porcelain. [substeps] As a general rule, any carved cameo made from a natural material can be considered authentic. 
Some of the materials used include shell, agate, carnelian, onyx, ivory, lava, coral, jet, bone, mother of pearl, and various gemstones. A cameo is referred to as being non-authentic or fake if it has been made with plastic or resin.