composed of silica spheres, which cause interference and diffraction of light. This unique internal structure gives opals their characteristic play of colors. The silica spheres are arranged in a three-dimensional grid-like pattern, where the spacing of the spheres determines the colors seen. The size of the spheres can range from a few nanometers to several hundred nanometers, and their arrangement can vary as well, leading to different patterns and color varieties within opals. Additionally, the amount of water content in the opal also affects its internal structure and play of colors.
