In the paper composed by James Lankton, Insook Lee, and myself, published last year, we demonstrate that there are no sound dates available to apply to typical jatim beads. We have pushed the limit, by suggesting a 7th century origin for some types. But it's still very up-in-the-air.

In any event, the idea that jatim date from ca. the 13th century sounds like a throwback to ideas we had when these beads surfaced in the 1980s—that they were Majapahit Dynasty beads. This notion was discarded quite a few years ago now.

Jamey