There isnt a glue line and it is definitely a natural stone, also as stated before, I wouldnt mind seeing if there is a label back there. Ive got an old barber that comes in the shop and hangs out that has a very nice belgian labeled hone I keep trying to get him to sell it to me....he had a labeled escher he bought in germany that when he shows me the length of it with his hands it had to be a 12 inch+ stone. He sold it several years ago though sadly but said he got 700 bucks for it....musta been a beastly escher