It might have happened but It didn't happen naturally.
Whether frozen or fossilized the skull would not have survived the amount of earth movement and alluvial action needed to concentrate the gold in an eye socket.
$1600 dollars of gold in 1906 would have weighed 6.5 pounds troy. That's about the size of 1/3 gallon of milk. To put it another way it would be about the same volume as 78 dice. In the eye of a skull. Right...
Maybe in Pennsylvania these type stories are believed but in the mining districts they raise little more than a laugh about how gullible people can be. Thanks for the chuckle.