Beautiful Chinese glass bead from the Warring States era of ancient China with elaborate "eye" decorations.  The base of the bead is a very dark bluish-green color, and is slightly transparent when viewed in the right light.  The elaborate decorations are a luminescent teal green and white glass, with the larger eyes comprised of three to six layers of alternating white and green layers of glass.  The eyes are slightly raised off the base of the bead and not quite flush with the surface.  Portions of the white decorations are somewhat worn, and almost "dirty" looking in places, and the entire bead has a somewhat fuzzy look.  The eye decorations on one side are somewhat distorted, and there is small hole between the white and teal portions of one of the smaller eyes.  Overall, however, the bead is just beautiful. 

The bead measures 21.0 mm tall by 23.7 mm to 24.4 mm (depending on whether you measure over the eyes or not).  Overall, the bead is approximately the size of a U.S. quarter or a 2 Euro coin. 

The Warring States Period of ancient China covers the period from 476 B.C. until the unification of China by the Qin Dynasty in 221 B.C.  Beads from ancient China have a high Barium content and other chemical constituents makes the beads heavier than most glass beads.  Of course, dating beads such as these is an inexact science, but this is our best estimate and consistent from what we've heard from other experts.  One short note on what I know of the provenance -- this bead was part of a collection owned by a Taiwanese woman, and brought to the U.S. by a reputable dealer after she died.  All of the beads in the lot were beautiful specimens.