Freddie Mercury may have had the golden voice, but real mercury, that endlessly entertaining and dangerous liquid metal, has the golden touch. That is, if it touches gold it will immediately break the lattice bonds of the precious metal and form an alloy in a process known as amalgamation. A process which, when catalyzed between a dab of mercury and a sheet of gold leaf, looks like the ignition of a metallic fire in reverse.
The fascinating, stop-motion-like demonstration comes from YouTuber and chemist NileRed, who leads us through the process of dissolving gold with mercury, and then reclaiming the former from the latter with the use of chemical treatment or boiling water. Each step is pretty magical, as the mercury gains and loses its gold content and goes from drop to blob to block and then back to drop.
The amalgamation process, where mercury breaks gold's atomic structural bonds and forms an alloy at low temperatures, also happens between it and and almost all other metals, including zinc, potassium, aluminum, and tin. The few exceptions include platinum, which means if you're going to be dealing with mercury, only the finest jewelry should be worn. Also gloves and lots of other protection because mercury is poisonous.
Although the process of amalgamating mercury and gold makes for great entertainment, it also serves a practical purpose for extracting gold from ore, as the gold can be extracted from the ore with the mercury, and then extracted from the mercury with heat and other chemicals. Although again, mercury is poisonous, which means this is horrible for the environment. Definitely still fun to watch in a lab though.
What do you think about this video of mercury dissolving gold? Do you want to put gold leaf on everything around your house knowing it's only $11 for 25 sheets? Give us your thoughts in the comments below!