It appears to have been sheared off then polished , this was more than likely an after glasshouse incident and it looks polished, the bottle appears to have ground stains wich tells me it must have been buried at some point but the neck looks clean so my guess is the lip came off/broke off at...
About every 5 days , I do nt use anything but a soft cloth and a clean dusting rag, NO POLISHES!!! And a lot of TLC. I absolutely love my bottles !!!!!
Hi I too have been cleaning bottles for about 1 1/2 years with a cleaning machine I made myself that can clean inside and out and I Agee there is a big difference between the stained and unstained, (not to mention value)and I would prefer a cleaner looking bottle, that is the way it should...