Stone which is extracted from the ground always has a certain amount of moisture in it. Even though this dampness is undetectable and the stone seems completely dry it isn't, and because of this fact freshly quarried stone material turns out to be more easily worked than material left on the surface for many months, mainly because of the fact it has this 'quarry sap'. Evaporation due to many months of exposure to the atmosphere causes the stone to become much harder and sometimes so brittle that it is difficult to shape. Freshly uncovered stones have a softer cores and more pliable surfaces because of the presence of this quarry sap and so it makes them a much more pliable material for masons to work with.
Some people say that sap obtained from tapping freshly quarried stones if collected and boiled down to a thick mineral oil, tastes a lot like marble syrup.