I was saddened to see that HercuGlass went out of business. Do you know of any other companies that sell hardened canning jars?
HercuGlass??? .... where are you living? .... all jars sold as "canning jars" have to be heat treated and hardened .... at least they are required in the US .... BIG difference between a retail pickle/mayo jar and a canning jar .... Ball is the largest canning jar and lid/ring manufacturer in the world .... they're sold everywhere in the world .....
interesting concept, shatter resistent glass that with stands thermal shock. I did some googling and couldn't find anything simliar. This was the first I had heard about HercuGlass, guess they closed due to not enough sales? You could try getting the contact info from the domain and see if they have any stock hidden away that you could purchase. Here is the info from "whois"