This is the biggest Copper Replacement Eye Agate I have found. I delicately removed this stone from its host rock which took weeks of careful chiseling.
The cracks are naturally occurring from the Copper being forced into the agate by hot thermal vents.
The slight red banding is from microscopic copper inclusions.
A highlight is this stone also has a spec of silver! Even a spec is extremely uncommon.
50x27mm!!