What is Dichroic Glass?

The word "dichroic" means two colors. This refers to the fact that the glass shows different colors depending upon the angle from which it is viewed.

For instance, one type is red when you look thru it and green when you see light reflected off its surface.

Dichroic glass was probably first made in the late 1800s  in Germany by Arthur Pfeiffer.  However, it was not until NASA developed the modern process for making it in the 1960s that it became inexpensive enough that it could be employed in glassblowing. (It is still not cheap: $100 to $200 a square foot.)

The manufacturing process consists of depositing many very thin (typically one atom thick) layers of special materials on the surface of a piece of glass. This must be done in an ultra clean environment in a special high-vacuum chamber. The materials to be deposited are placed in a cup in the bottom of the vacuum chamber and bombarded by an intense electron beam. This beam vaporizes some of the material which then coats on the sheet of glass.

The result is a uniquely interesting glass.