I measured mine, and it's only 3/16".Try somewhere that carries glass...especially places that carry glass to cover wood tables...Good Luck!!!

Youghiogheny Station,a gallery I purchase from, carries various sizes of the glass rounds.They also sell rectangular PPG sheets, but I found them too thickm and very difficult to cut. If you purchse a round of glass, perhaps to sit on top of a table, that could be used, but I don't know how expensive that would be.Youghiogheny Glass Factory is having a sale beginning March 18th-20th in Connellsville,PA.Don't know where you're from,but it's worth the trip.They come from all over the US, even Canada!!

I used Weldbond glue.