Glass Colored by Radiation
The amber-brown color of the glass on the right was produced by an exposure to cobalt-60 (Co-60) gamma rays. The absorbed dose was on the order of one megarad (one million rad). The glass on the left is identical except that it was not exposed to gamma radiation.
The color that glass turns as a result of an exposure to radiation depends on the type of impurity in the glass. In this case the "impurity" is lead. By weight, the glass is 20 to 30% lead.