Density of gold: 19.320 g/cm3

Gold is quite heavy, as anyone who has ever held a bullion in his hand knows. However, the fact that gold is one of the heaviest materials on earth might come as a surprise for some. In order to compare the specific weights of different materials, the density, i.e. the quotient of the body mass and the volume of a substance, must be calculated. The density of gold is exactly 19.320 g/cm3. If gold were not so rare, the well-known saying would certainly not be "heavy as lead", since lead has a density of 11.340 g/cm3 and is therefore much lighter than gold. It is certainly not surprising that aluminum has a mere seventh of the density of gold – but if you compare gold with construction materials, you might very well be surprised: gold is more than ten times heavier than concrete, and its density is more than three times higher than that of the heaviest reinforced concrete. Only the transition metals osmium, iridium, platinum and rhenium have a slightly higher density, at 22.610 g/cm3, 22.560 g/cm3, 21.450 g/cm3 and 21.040 g/cm3, respectively.

The enormous density of gold has not only made it easier to extract ever since the historical beginnings of the hunt for gold (think gold panning), but also makes counterfeiting the precious metal with the help of cheap alloys extremely difficult. The only metal that has the almost exact same density as gold is tungsten with a density of 19.300 g/cm3. Tungsten also has a melting point similar to that of gold. However, tungsten is also very rare and therefore quite expensive, albeit cheaper than gold. In the past, elaborate forgeries of gold bars and coins using tungsten have been produced, but these fakes could easily be identified by means of a simple test using a strong magnet: tungsten is paramagnetic and therefore attracted by a magnet, while gold is diamagnetic, i.e. it is repelled by magnets.