You may have seen beautiful jewelry described as "bi-colored" and wondered what exactly that means? Dichroism comes from the Greek meaning two colors. The glass appears in different colors when viewed from different angles or with varying degrees of light. Basically, it means that dichroic glass reflects one color when light is reflected from the surface and transmits a second color when light passes through it.
Dichroic glass today is an offshoot of the space program as it has been used in face panels to filter out unwanted spectra of light. Dichroic glass today has many different applications from fine jewelry used by artists to the optical and security industries. You can find the etched dichroic glass from Art Glass Supplies.
The process used to make dichroic glass is very technical and is called "thin-film physics". It is an expensive process in which glass is first cleaned to the molecular level and then coated with thin films of elements such as titanium, magnesium, zirconium, and others. Elements are deposited by vacuum on glass. Up to thirty layers can be applied and the elements used to give the glass the different colors available. The time required in the vacuum vessel can take from two and a half to four hours, hence the reason for the high cost of this unique glass.
Artist's glass is sold as small sheets that are hand-cut to fit the artists' design and baked in an oven for eight hours or more at temperatures that can reach 1,490°C. Dichroic glass is also available in lamp artist glass rods to produce beautiful beads. Lamp artists use a torch and rods of glass to produce the beads on a mandrel that is also placed in an oven for about an hour to solidify.