How did the ancients carve hard stone such as granite without modern tools. Some great statues were carved out of the stuff when the only metals in use were copper or possibly bronze. No tool steel or carbide existed.
The philosophers have only interpreted the world in various ways; the point, however, is to change it. (Karl Marx, 1845)
They relied a lot on cleavage. No, not the feminine kind, but the way rocks split when struck with sufficient force. By driving small wedges into hole drilled into the rock (and yes, this can be done with soft metals), large rocks can be quarried. Look at the pyriamids, for example.
I remember seeing a program (NOVA?) that said the Mayans used abrasion some, but I can’t recall the type of rock that was being used. Granite would abrade granite enough to sharpen or plane most surfaces that weren’t cut exact in the original removal of the block.
Fact is stone can be carved without metal tools at all. Examples of this exist throughout Polynesia. The Easter Island statues and all those Hawaiian “tikis” where carved by cultures that never developed metals of any kind.
Exactly which great statues are we speaking of, so we know what was being carved with what?
There’s a lot of ancient statuary dating back to the Babylonian/Assyrian periods, but these were people who had discovered copper and iron, which was hard enough for the stone they were carving (in other words, they weren’t carving granite, but limestone, sandstone and other “soft” rocks).
Polynesian cultures may of worked with harder rocks, but then again, most of their carvings weren’t exactly photorealistic. Cleavage and simple banging of a pointy stone against a flat stone can account for most of the carving. Likewise for monolithic structures such as Stonehedge. Find a big rock in the vauge shape you need, bang on it with other rocks until you’ve shipped it down to how you want it, then set 'em up.
By the time we see any real detailed carving in things such as marble or granite, mankind in those areas already had steel tools (remember, steel has existed since Biblical times) which would do the trick.
“I guess one person can make a difference, although most of the time they probably shouldn’t.”
“Using stone tools to carve blocks from nearby volcanic outcroppings, they constructed an intricate weaving of bui ldings, platforms, plazas and courtyards.”
Simple, you have a big rock and a lot of little rocks. You want to carve the big rock. You pound on it and chip it it with one of your little rocks. When one of your little rocks wears away too much to use, you through it away and get a new little rock. You go through a lot of little rocks, but you eventually get a carved big rock (and a lot of rock fragments). What’s the problem?
This sounds like you know the answer (or at least an answer) and are treating this like some kind of test. So, are you asking or fishing?
“Drink your coffee! Remember, there are people sleeping in China.”
I neglected to mention that you could stop by your local monument works and grab a couple of castoffs for little to nothing. Hammer at one with another until you’ve got the shape you want.
I once, as a Boy Scout, flaked obsidian with a deer antler tool (without cutting myself, which was the hard part).
taanstaafl has it right. If your tool is only as strong as your target it will wear quickly, but that just means you have to replace it more often. It doesn’t mean you can’t do it.
A slight refinement is that what is needed in a tool is not hardness but toughness. In my personal example, the obsidian was actually harder than the antler but the obsidian was very brittle. The obsidian would break under stresses that merely bent the antler.
“If ignorance were corn flakes, you’d be General Mills.”
Cecil Adams The Straight Dope