Why Can’t We Burn Stones?
We cannot burn anything that has already been burned, and a stone has already been burned. To understand how this is we must first find out what takes place when a thing is burned. When a thing is burning it means merely that that particular thing is taking into its system all of the oxygen of the air that it can combine with. When it has done this it cannot be burned any more. Of course, in doing this the thing originally burned changes its character. The elements in a candle when lighted mix with the oxygen in the air and disappear in the form of gases. The elements in coal mix when fired with oxygen and change into ashes, gases and smoke. A stone, however, is the result of a burning that has already taken place. The original element of most of the rocks and stones we see was silicon, and when that combines with oxygen, the result is some form of rock, which you may be able to break up or throw, but which you cannot burn again.