if you shine a torch over the surface, you might be able to see a little wear at the right angle.
But fingernails are really very good, unless you chew them.
![Wink ;)](http://www.glassmessages.com/Smileys/classic/wink.gif)
My Grandpa had cocktail glasses very similar to this, with the same sort of cutting on the bowl (not on the base) and the stems were amber. I thought those were Bohemian - a different colour of stem and base with a clear bowl often does, to me.