Muze Of Confidence
Dichroic glass is glass containing multiple micro-layers of metals or oxides which give the glass dichroic optical properties. The main characteristic of dichroic glass is that is has a particular transmitted color and a completely different reflected color, as certain wavelengths of light are either passed through or reflected. This causes an array of color to be displayed. The colors shift depending on the angle of view.
The thermal expansion coefficient of the glass used at processing determine the color of the coating. Due to the different quality of the materials and the different thickness of the layers, sometimes we don't get the exact same color as last time. The color range is huge, over 45 hues.
Modern dichroic glass is available as a result of materials research carried out by NASA and its contractors who developed it for use in dichroic filters. However, color changing glass dates back to at least the 4th century AD, though only a very few pieces, mostly fragments, survive. It was also made in the Renaissance in Venice and by imitators elsewhere; these pieces are also rare.