scarab

The scarab had significance as a religious symbol in Egypt and soon spread into Phoenicia, Etruria and Greece, where it became a timeless motif of design for jewelry. Egyptians dealt only with soft stones, while the Assyrians could take advantage of a harder surface, since they had the drills lacking in Egypt. The form of the beetle was carved into the top of the stone, while the flat base was carved the name of the owner, the reigning king and symbols of certain deities.

When the scarab was set in a ring it possessed a particularly efficient combination of desirable uses, especially in the realm of the amulet. Scarabs served this purpose before they reached the point of development where they took the first step toward being used as signets. It was this instance intaglio was developed. This is a method of cutting, where the stone is hollowed out instead of the design being raised above the surface. This aided the change from the scarab being a simple amulet to its use as a seal. The seals were used to stamp any property or document with the owner’s mark. These were then bound to him and he to them by a link of magic.

http://www.guyotbrothers.com/jewelry-history/jewelry-history-page4.htm