The dzi (zee) is a uniquely Tibetan stone, an agate of oblong or round shape pierced lengthways. It has a shiny black and white design, characterised by the strong eye pattern, circle and square or double wave.

The most valuable dzi were those with three or nine-eyes, the best being those with sharply contrasting patterns, shiny and with a faintly oily surface.

There are many interpretations concerning the dzi's origin. Since they are usually found buried in the ground, it is generally thought that they were made and worn by people in prehistoric or neolithic times. There are more mystical interpretations, some being that the dzi were once worm-like insects which, when frightened, froze and turned to stone. Other stories relate how the dzi were once ornaments of the demi-gods who threw away when they became damaged, which accounts for why so few of the beads are in a perfect unblemished state. They were said to appear in miraculous ways, sometimes as presents from local deities to humans who had rendered them service and appearing out of rabbit holes or on bushes which bore them like fruit. The dzi is either worn as a single bead about the neck, mainly for its auspicious or medicinal value, or in a traditional necklace interspersed with coral, pearls, amber or turquoise, or even, if the owner is fortunate to have a collection of dzi, a whole necklace is made from the stones. Dzi are also used when applying gold to thankas or writing in gold, to burnish it and bring out the sheen.