Unknown Decanter/Pitcher

My sister recently purchased the decanter and glasses below. I am trying to identify hoping to find more of the glasses. The decanter is approximately 16" high and the glasses are 6" high. I am going to say the color would be yellow/amethyst. Thanks for any help in identifying or suggestions for further research.

Lovely. I think they are American. I would ask here http://www.chataboutdg.com/

Thanks Christine for replying. It is actually on the chataboutdg site as well. I recently went to a glass show and spoke with some glass dealers and most thought that is was European.

I also received a comment on chataboutdg and that individual also thought European.

Thanks again for responding.