Dichroic glass is made by coating a thin substrate of glass with multiple micro-layers of metal oxides which have the property of transmitting one colour while reflecting another. This gives a distinctive ‘sparkle’ to finished pieces.
Dichroic glass was originally developed by NASA and its contractors for use in satellite optics and spacesuit visors.
Manufacture
Multiple ultra-thin layers of different metal oxides (gold, silver, titanium, chromium, aluminium, zirconium, magnesium, silicon) are vaporised by an electron beam in a vacuum chamber. The vapour then condenses on the surface of the glass in the form of a crystal structure. This is sometimes followed by a protective layer of quartz crystal. The finished glass can have as many as 30 to 50 layers of these materials yet the thickness of the total coating is approximately 30 to 35 millionths of an inch (about 760 to 890nm). The coating that is created is very similar to a gemstone and, by careful control of thickness, different colours are obtained.
(Information from Wikipedia)
