Hi Michelle thanks for writing in. It is hard to see from this image but you mention the cherub is "painted on" the surface so I'm wondering if this finger ring actually falls under the category of porcelain jewelry. Some porcelain jewelry has flat plaques of porcelain and decorated with floral designs, sentimental motifs and miniature portraits, etc.
Does it have any markings on the inside of the band? These marks (if present) will provide dating clues and also affect the value.
A cameo on the other hand is a relief which is cut so that it is raised up. An Intaglio is the name for engraving with negative image, as used for seals. You can find more info on Antique Cameo Here.
