>>12480289more specifically, geopolymer. Yet some of the best examples are out of solid granite (or even harder rock) and would have had to been carved.
Even in egypt, it would've taken more than a thousand people to drag those coffins down into the tomb, yet there are no marks on the floors. There wouldn't have even been enough air to keep them alive while doing so. They'd suffocate.
All of these intricate passageways and traps under a million pounds of stone tomb in pitch blackness, yet not a single bit of soot on the ceiling. And these aren't even the best examples. The best, lay underwater off of coasts, all across the globe, where bare land has not been for tens of thousands of years.