Mercury is a very strange metal.
It is a liquid at room temperature, but it is so dense that cannon balls float in it.
With the atomic number 80 in the periodic table and with an atomic weight of 200.59, this element is heavier than lead.
Mined as the ore Cinnabar, mostly from the Quavos mine and the Almaden mine, this ore is then ground up, producing Vermillion. This was used by the artist Rubens in his famous painting "the three graces" as the blusher on the faces of the ladies. This was rather appropriate, as at the time the painting was done, Vermillion was used as blusher (despite it's toxicity).
After it is fairly powdered, it is then heated, and at 357 degrees centigrade it the mercury boils out of the rock. Because of the low boiling point it is very easy to produce very pure mercury. This turned out to be very useful in 1908, when Camelling Onnes made use of this property and it's relatively high resistivity to prove the concept of superconductivity (which he ended up getting the nobel prize for).
Because of it's low boiling point, it was very easy to use mercuric oxide to produce pure oxygen. In fact, this proved incredibly useful for Priestley and Lavoisier in 1777 to use to help in the development of the foundations of modern chemistry. It was essential in Lavuosier's final defeat of the phlogiston theory, when he proved resperation to be a slow form of combustion.
The strange properties of mercury were also useful to Michael Faraday, who took Orsted's observation of the deflection of a compass needle by an electric current and used it as the basis for formulating the rules of electromagnetism.
Mercury is also a member of the thermoelectric series. In combination with silver it forms a dendritic structure know as the tree of Diana, but if you have a higher percentage of mercury it forms a liquid. Mercury forms an amalgum with gold.
PS
Health impacts of lead poisoning.
