An opaque bright red pigment of mercury sulphide occurs in a nature as the mineral cinnabar and has been in use from antiquity. The Romans, who loved cinnabar, sourced it from Almaden in Spain, the great- est mercury mine in the classical world.
In the 16th century there were two punishments for prisoners: the galleys or Almaden. A lucky man got sent to the prison ships.
Vermilion, the synthetic form, was invented around the 8th century. Mercury and sulphur are united through heat to form a red substance. In the Middle Ages its marriage of fundamental substances (sulphur was understood to be base gold) made it of incredible interest to alchemists.
“Take one part of mercury and one of sulphur. Put it in a glass bottle, thoroughly clad with clay. Put it on a moderate re and cover the mouth of a bottle with a tile. Close it when you see yellow smoke coming out of the bottle, until you see the red and almost vermilion- coloured smoke. Then take it from the re and the ver- milion will be ready.”
This resulting lump was then ground: ‘If you grind it every day for twenty years, the colour would still be- come ner and more handsome.’
The pigment was the principle red in painting up until the discovery of cadmium red in the 19th century.