Fire Color
Fire color refers to the color flashing out of the opal caused by the optical phenomena called diffraction. Since these colors are produced by light, they can be all the colors of the rainbow.
There is an interesting physical phenomenon in regards to the fire color. If you move the opal, some splashes of fire change color. As the angle of light changes, you move up and down the color spectrum. Other splashes of fire keep the same color but move across the surface. These color changes are what make the opal so fascinating.
