Due to the overall dark color of the bead, to get the correct exposure I had to take the attached photos in the direct sun. I guess they could have turned out worse, but there are bright spots.

Background: the bead is approx. 10.5mm in diameter; the perforation about 2mm; the bail and end cap appear to be sterling and hand-worked; the top glaze appears to be lead or similar; the colors (esp. blue and green) are not enhanced, and are as brilliant in person. The bottom portion of the bead is defined by an undulating solid black field; the upper portion field has varying shades of tan-brown with apparent splotches/washes of a darker brown and a brighter yellow color. The yellow I cannot see with the naked eye. This bead came in a set of four, all with matching bails and caps; the other beads are jade (11mm), coral (10mm), and carved cinnabar (13mm).

There are six photos: the bead was rotated slightly for each of four shots, and there is a top view and an angled bottom view of the signature area, which is outlined with a black line. At this time the signature is assumed to be that of Japanese ceramist Kenzan Ogata (1663-1743), but the bead is assumed to be probably/possibly much later, in the "Kenzan style". The characters making up the signature are 2-3mm in height.

What is known about this bead to date is not of my doing; Thanks and kudos go to Frederick II, Beadiste, and of course Will for their expertise, persistence, and the generous sharing of their time. Thank you!