Large Unmarked Costume Brooch with Green Glass Stone

I just want to share this brooch with you because I fined it rather elegant. I really like the simple lines.

The brooch has a beautiful large glass stone in a gold-tone setting.

I think it might date back to the 1970's, however, this is just a guess. I spent some time searching for a similar Brooch but so far have not come up with anything.

Any ideas would be greatly appreciated.

Thank you for looking:)