The art of glyptics, or carving on colored precious stones, is probably one of the oldest known to humanity. Intaglios, gems with an incised design, were made as early as the fourth and third millennia B.C. in Mesopotamia and the Aegean Islands. They display a virtuosity of execution that suggests an old and stable tradition rooted in the earliest centuries. The tools required for carving gems were simple: a wheel with a belt-drive and a set of drills. Abrasives were necessary since the minerals used were too hard for a metal edge. A special difficulty of engraving intaglios, aside from their miniature size, was that the master had to work with a mirror image in mind. On this beautiful bloodstone is engraved the head of the deity Tyche. She is one of the most appealing and popular goddesses of the ancient world. She has no myths connected with her, being more of a concept as the deified personification of Chance and Fortune. Every city had its Tyche, depicted as crowned with towers to symbolize her role as a guardian of cities. On a more personal level, Tyche has continued on into the modern era as "Lady Luck", dedicated to bringing prosperity to whoever has the style and sophistication to wear such an unusual ring.