The correct answer is solid rock
The Egyptians used a very clever trick. They flooded everything and dug ditches as deep in the limestone soil. Then they drained the area, so that the water remained only in the channels they had made. Then, you just had to be guided by the water level when cutting the “excess” of soil
Most of the blocks were extracted from a quarry 300 m away. Historians speculate that workers used copper instruments to make cuts in the most superficial parts of the limestone rock. Then they would stick wooden wedges and water them. It expanded and separated a block from the rest of the stone.