A signet ring is a ring bearing on its flat top surface the equivalent of a seal. A typical signet ring has a design, often a family or personal crest, created in intaglio so that it will leave a raised (relief) impression of the design when the ring is pressed onto liquid sealing wax. The design is often made out of agate, carnelian, or sardonyx which tend not to bind with the wax. Most smaller classical engraved gems were probably originally worn as signet rings, or as seals on a necklace.