The incredible flashes of colour in opals – often called "fire" or "play of colour" – are the result of microscopic silica spheres packed tightly inside the stone. These spheres diffract light, bending and scattering it into different wavelengths, depending on their size and arrangement.
This phenomenon creates dazzling rainbows that dance across the surface as the stone moves. No dyes, no filters – just pure natural physics, perfected over millions of years.
It’s this unique internal structure that makes loose opals so fascinating to look at and so treasured in jewellery making.
Did you know?: It wasn’t until the 1960s that scientists finally discovered the answer. Using an electron microscope, they found that opals contain tiny silica spheres, arranged in a neat, three-dimensional grid. This natural optical wonder is what gives precious opals their hypnotic beauty, and no two stones will ever show exactly the same pattern. It’s light and science, captured forever in stone.