When i said i have no clue i may have been giving myself too much credit. I truly would not know.
Now that i looked at the other photo(the link didn’t appear in the ping) that you so kindly provided that rock was clearly part of another rock at some point in time. there are no smooth looking areas such as we see in the nugget.What we see on that side of the nugget looks nothing like the hygraded gold in your link.