1,146. A Signet Ring
168:3 Regarding a ring with a seal in the shape of a person, if it is raised, it is forbidden to retain it. It is, however, permitted to seal documents with it because it makes a sunken impression. If the seal is sunken, one may retain it but he may not seal documents with it because it makes a raised figure.
168:4 It is prohibited to stare at an image of a person since it is considered an idol. Doing so violates Leviticus 19:4, "Do not turn to idols." This does not include the images on coins, which are familiar, though the pious are careful in this as well.