Here is a slide from my Powerpoint presentation at the 2004 San Jose National on altered insulators. The final sample insulator from this experiment is now part of the NIA Altered Insulator Educational Exhibit. The left photo is the original manufactured color of the sample insulator. The center photo is the same insulator after radiation exposure. The right photo is the same irradiated insulator after controlled high heat exposure. This is only a sample of the varying color shades that could occur in this particular manufacturer and style. Myriads of color and shade variations are possible due to the varying chemical content of each glass batch. Be sure you know what you are buying and who you are buying from, especially when an unusual color is being offered. There are many irradiated insulators entering our hobby daily through sales on the Internet, swap meets and antique shops. Do not promote this unethical practice by purchasing irradiated and altered insulators at any price. The future of our hobby may depend on it! More info at: http://www.nia.org/altered/index.htm