This simply isn't possible. Firstly granite is an igneous rock, while it's chemical formula is pretty much the same as most other rocks, its structure is much different. This structure requires extreme heat an pressure to form. Regardless, forget about that for a second and think about the chemical reaction. If you react SiO2 with an acid you would get a silicic acid. If you react that with a base you get a salt not SiO2, the oxygen gets converted into water in the first reaction and in the second it forms a hydroxide ion. Which means you would have to react your acid with say aluminum oxide to reform your SiO2. Of course then one wonders how the heck they are mining aluminum ore and why they didn't continue the refining process that they started to get pure aluminum. Regardless, that still leaves the whole heat and pressure problem. So unless chemistry and geology have changed dramatically in the last few thousand years...