I haven't been able to find the Cashel website for some time now. But "Yes", there was a glass trumpet (more correctly, crystal). They were available as an almost complete crystal instrument with a "standard" valve block. They also sold a conversion kit that would put a crystal bell onto a "donor" horn.
There is also the ceramic trumpets but these aren't really playable (although apparently you can make some kind of noise on them).
These to be found at:
http://members.ispwest.com/clay/bugles.html and a sample is:
