Kentucky there are 3 furnaces near me but 2 are on the gov., I have a chunk of a darker color ,my green is bubbly too , most of what I found is real small peices , I am going to wait till they clean out the ditch and it rains again and maybe I can find some more it is only about a couple hundred yards from the ruins ,they must have dumped it in the road ,way back in the 1800s.