[yarddog]

I once read that the Egyptians used copper chisels with hardened tips. Unfortunately they didn’t explain how they hardened them.

Maybe there is a known way to do it?

[Windflier]

I once read that the Egyptians used copper chisels with hardened tips. Unfortunately they didn’t explain how they hardened them.

That's the answer Egyptologists always give to get around that thorny question, but no one's ever shown how you can harden copper to the degree that it can carve granite.

Obviously, there's an answer, because the hieroglyphs are there, but how they got there, is something the ancients never explained. Neither can modern archaeologists, it seems.