I have a green insulator that I've had since I was 14. I just cleaned it up last year over 40 years later and found it has amber swirls in the green glass. I had no idea all this time. Love the heavy feel of the glass insulators, built to last.Definitely they look beautiful. Sometimes I look for embossing errors on common pieces. Today I was looking through my “cheap insulator” collection, and found a piece that is aqua with amber streaking. It was covered is so much dirt that I hadn’t noticed.