There are two things to keep in mind. Rafaello and Michelangelo worked with stone that wasn't nearly as hard as granite (granite being one of the hardest stones). Secondly, we don't believe metals were nearly as developed during the period of dynastic Egypt and some Egyptologists theorise (but I think this is crazy) that stone tools were used to carve the blocks.

Granite? Who crazy would come up with the idea to build pyramids with something as heavy and hard as granite.

They were not even carved out of limestone blocks, they were casted by an early form of concrete created using a mixture of limestone, clay, lime, and water. Similar to how they would have been built nowadays. http://www.livescience.com/1554-surprising-truth-great-pyram...

The walls of the king's chamber are pink granite. They also happen to be some of the more precise work in the pyramids.