Multicolor

Multicolor is the entry recorded in this atlas under the gemstone colour value multicolor, for stones that do not show one body colour but several, or a colour that changes with the light. Wikipedia describes iridescence, one way this happens, as the phenomenon of certain surfaces that appear gradually to change colour as the angle of view or the angle of illumination changes, and lists the mineraloid opal among its examples. It stands for the bucket, not for a single hue. It is recorded as its own colour entity so that the gemstones of this colour can be grouped and compared in one place, while each gemstone entry keeps its own colour fact and sources.