Dichroic, from the Greek dikhroos meaning  two-coloured, describes  any optical device which can split a beam of light into two beams with differing wavelengths. These devices include mirrors and filters, usually treated with optical coatings, which are designed to reflect light over a certain range of wavelengths, and transmit light which is outside that range.  When applied to glass, it refers to glass containing multiple micro-layers of metal oxides which give the glass dichroic optical properties.
Its invention has sometimes been attributed to NASA, but, in fact, the Romans were using dichroic glass in the 4th century AD as seen in the Lycurgus cup (pictured below).

To manufacture dichroic glass, multiple ultra-thin layers of different metals (gold, silver), metal oxides (titanium, chromium, aluminium, zirconium, magnesium) and silica are vaporised by an electron beam in a vacuum chamber onto base glass. The vapour condenses on the surface of the glass  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 890 nm). The coating that is created is very similar to a gemstone and, by careful control of thickness and the angle of the glass in the vacuum chamber, different colours are obtained. Over 45 colours of dichroic coatings are now available to be placed on any glass substrate.

Glass artists can now get dichroic glass from dichroic coating manufacturers and may fuse it with other glass in a series of firings.  As the firing process may vary each time, the final result can never be predicted and so each piece produced by the artist is unique. This explains why dichroic glass beads, pendants and cabochons tend to be quite expensive.

Unable to resist the allure of the rich jewel tones, we have started a small range of beads, pendants and cabochons.  Please bear in mind that these are hand made and that  colours and designs may vary from piece to piece, making each one unique.  The pictures below are simply a guide to the shapes and colours that are available at various times.

Back to Special beads

Home