What Is the Common Denominator of Resources?

A shovel equal equalling three coats, for example. The value of an object is going to be determined by the amount of labor that was quired to go into it. So in the case of a shovel, if it took, say, a laborer ten hours to make, plus however much the resources cost. And i think it's important here to mention that when we discuss resources like the metal that goes into a shovel, or the wood that goesinto a shovel, none of these things has value in itself.