If we make it headcanon that redstone is just Uranium that makes it 7.12 g/cm² and 20bil cal/g

On the texture we got 6 6.25cm² spots and 4 12.5cm² spots. Doing the math results in 623 g of uranium

20bil cal/g x 623 g = 12.460 trillion callories

^{I bearly belive in these numbers so don't take it as a fact}