Thank you for your comment.
At first I was thinking the bead was a kind of Jatim in half, and then cold worked, and drilled.
It's the most natural way to think about this bead.
I think everybody think so at first.

And I agree the hole of this bead is drilled .
And there is the trace of original hole on it's belly in fact.
(I didn't open it because I wanted to let you think without preconception.)

But the mosaic layer of this kind of bead is very thin normally.
The fact made me to think "cold work" can't make this bead.

If it had very thick mosaic layer, you may be able to make it by carving.
But if it has thin mosaic layer like Jatim, you can't make it only by carving, I think inner layer comes to appear more and more around arms and legs and back like it's neck you pointed.

I have not reached clear idea yet.
And anyway I'm sure any works(cold or hot) had been done in ancient time.

SHINJI