Pyramids in Egypt. Photo: GLF Media / Shutterstock.com The pyramids used to be smooth, white, and blinding in the sun. Now they look like giant ancient staircases, and the usual explanation is that people stole the good bits. History for Granite says the truth is messier and far more interesting. The simple story is that people stripped the pyramids for building material. That happened, but it does not explain everything. Looking at the damage patterns, History for Granite argues that some pyramids were not quarried directly so much as shed their casing stones through natural forces, with people later hauling off what had already fallen. That makes the Bent Pyramid especially important. It still has much of its original white limestone cladding, making it one of the best surviving pieces of evidence of how the Egyptians finished these monuments. It is also still suffering the same forces that may have stripped other pyramids bare.…