Depends on the environment, of course. In the ocean or Lake Superior, sharp glass gets rounded to smooth pebbles within 100 years. I’d estimate the sharp edges

Depends on the environment, of course. In the ocean or Lake Superior, sharp glass gets rounded to smooth pebbles within 100 years. I’d estimate the sharp edges take 20-30 years to disappear. Sitting still on a street, of course, not much will happen. As far as areas of expertise, I am a veteran (20 years) glassblower, but I am not an expert on how glass decays at all. I’m skilled at making it into things.