That's a beautiful bead and really long - nearly 15 cm. Wow! I don't recognise the name Tsakli as being that of any Neolithic or Bronze Age site in the region, but 2 hours north of Bangkok (allowing for traffic jams!) would take one to Lopburi and there are several sites around there where tubular beads like this are occasionally found. More typical would be the smaller hardstone beads that have a double function as beads and ear ornaments (see the attached photo).

A lot of the long nephrite (and sometimes serpentine) tubes are found in the Ban Chiang area, but the only place where evidence of manufacture has so far been uncovered is at the Phung Nguyen site of Trang Kenh on the coast at the mouth of the Red River estuary east of Hanoi. The Vietnamese archaeologist Nguyen Kim Dung made the discovery in the late 80s and I've seen the massive quantities of beautifully worked hardstone bangles, rings, beads and ceremonial adzes that were recovered there and which show the various stages in the process of production.

For the moment, I'm inclined to believe that all these tubular beads from that region and period (early 2nd millennium BCE) were made in northern Vietnam, but many of my Thai friends would disagree vehemently.

(Incidentally, a word of warning to anyone reading this: the English-language Wikipedia entries for Vietnamese prehistoric cultures are frequently wrong. I don't know why, and I've given up trying to correct factual mistakes in Wikipedia; it can become a full-time job!)

Cheers,

Will