Opal

Opal is known for its stunning play-of-color, which is the result of the diffraction of light as it passes through microscopic silica spheres within the opal's structure. Opal comes in a variety of colors, including white, black, blue, pink, and green, with some specimens exhibiting multiple colors in a single stone. Common opal lacks play-of-color and may appear as milky or translucent with a single, uniform color.