Uwe,
As with you this is not the first time I have had an oops and assume it will not be the last. I saw a slight crack in the black glass on one of the facets so I knew I may encounter exactly what happened. I can just change my angle and get a wonderful facet cut bead just not the one I thought I was going to have. It was just a shame that such a perfect piece of glass work did what it did. As they say "that's part of the sport"

As you do, I love what I do and I always strive for perfection knowing I will never achieve it ........ Sure fun trying.

All my best ...... Danny