Application of a hot soldering gun tip to the slab softened the adhesive and
allowed me to scrape it off with the chisel. It was all over in 10 min. and
with nary a scratch on the crystal. I don't know what kind of adhesive they
used, but it was incredibly tenacious on a polished glass surface.

Sure sounds like UV cure cement. Application of heat to begin with would have
taken it off without the physical trauma.

Earle Rich
Mont Vernon, NH