Hi,
I've flown with glass a couple of times.
Last year I brought a framed & glassed picture back from the USA in my hold luggage. The case was opened somewhere in transit and they attempted to get the back off (presumably thought it was drugs? money?). They couldnt get it back together again afterwards and just dumped it back into my case

It did survive tho, so that was OK.
The year previous I brought a glass paperweight back in my hand luggage. The journey included some USA internal flights, and at EVERY SCANNER I went thru I had to get the paperweight out and unbox and unwrap it to prove what it was. I was so sick of it by the end that I wished I'd put it in the hold
Cheers,
karen