Opalized crab claw fossil, a rare geological occurrence where organic material is replaced by precious opal.
The fossil dates back to the Cretaceous period, roughly 66 million years ago, when the area was covered by an inland sea.
It was found in Lightning Ridge, New South Wales, Australia, a region known for ideal conditions where silica-rich groundwater replaced the original exoskeleton.
The vivid colors are entirely natural and are caused by the diffraction of light through microscopic silica spheres within the opal.


















