[Speedslug]

I got some from some reseller that came from a monster glass chandelier.

But without a excellently controlled warming and cooling kiln it breaks without the slightest provocation when you try to work it.

That was one of the main reasons the scientist community developed Boro in the first place more than a century ago.

The Masters in Italy can make sculpture with soft glass but you never see them heating soft glass a second time unless they are attaching more glass and even then they keep things small like the size of a fat rod of soft glass.
Say maybe 10 mil or maybe a fat finger thickness.

And its always solid, not tubular.