Crafting Quarried Stone to Quarried Block seems to reduce the available quantity by 1/4. It is a 2x2 (4) to 1 ratio. From the law of conservation of mass, it should produce 4 Quarried Block.

Using railcraft-12.0.0-alpha-9

Well mining them doesn't drop the cobble stone variant, so that might actually be a bug too. It drops the smooth stone variant.

it should drop the regular stone variant. (quarried stone) that's intentional. then you cook in furnace what you pick up after mining

Hmm, aren't you supposed to cook them into blocks?

There is no furnace recipe for Quarried Stone.

should be a bug then.

You can crush quarried stone in a rock crusher, then smelt it. This process has a 1-1 ratio, but requires Railcraft infrastructure. I think it's fair.

Decided. Reverting to the old recipes.