Thanks 3B!bearsbearsbears wrote: In the end, I don't think it's all that important, but it's an interesting question
Beautiful "glass" bottom!
Great info too.
Don't you think the possibility of the presence of lead (from recycled glass or from marbles) is important?
edit/add - I notice (see my last past - I think I was writing it as you posted) that there is no "murky" border around your "glass" bottom. Is this indicative of silica fritt then (no weird border)?