Hi Will
How do you do?
I got depression so I leave for some time without doing anything.
Thanks very much for your reply!

When talking about tubular beads from east asia, it is really a great topic.Early tubular beads could be found from north korea(one of my early posts on this forum is about tubulor beads from that region)to south vietnam from different period of time and different kind of material.

The first attachment is from "Jadeware from East asia" a very good book on early jadeware published in taiwan china. But there is no provenance about these beautiful beads made of as you said a dark green almost black jade.During the 1990s the economic condition in taiwan was on its top so the dealers and collectors were very active and many ancient antiques especially jadeware from other places of asia flowed into taiwan.so I think these beads were bought during that time from some place like south china or south asia countries.
they are very much like your bead isn't it? though maybe becouse of the photograph I can not see very clearly the material of your bead I am sure it is very old.