 FACT: Hudson Hawk is given a brick of gold and a brick of lead while  blindfolded to demonstrate that they are indistinguishable by  weight. Gold is 70% more dense than lead and the weight difference  of those bricks would be easily noticed. A gold brick of that size  would weigh about 30 pounds, but they handle it as if it weighs a  couple of pounds. It is also mentioned that gold and lead differ by  one proton on the periodic table of elements, but they differ by 3  protons (and about 7 neutrons).