A locket is the one piece of jewelry with something hidden inside it, and that is the whole reason people buy them: a photograph of a child, a parent, someone no longer here. These are 14K white gold hearts, polished, engraved or set with small stones, and most take one or two photographs.
See also yellow gold heart lockets, sterling silver heart lockets, rose gold lockets and all locket pendants. Pair one with a white gold chain.