Actually, I think your three types relate not to a basic difference in the beadmaking technology but to the state of preservation of individual beads. Sometimes, the material used to form the pattern (glass or enamel) hasn't attached itself very effectively to the core of the bead, but when the process has been more successful it has become embedded in the glass; and sometimes subsequently it has been worn away by use or burial conditions.

In any case, all the beads you found are very interesting. I would have loved to see them. In what region of East Java did you find them and do you know anything about the conditions in which they were dug up? I was in Jember myself last year, but I think you're a much better hunter than I am!

The bronze duck-shaped pendant is a great find. I haven't seen anything like it from Indonesia. What size is it? Bronze bird shaped pendants and appliqués were common in Central and West Asia, but I haven't seen one in Southeast Asia. How big is it? Birds are common decorative patterns, as were sun designs, on bronze drums from the Dong Son culture in Vietnam several hundred years before the glass beads were made, (see the drum face pic), and some of these drums were actually exported to Java - which may explain why these patterns were later used on Jatim beads.

Best,

Will