Cinnabar means to gild silver and gold to objects) "the toxic properties of mercury were well known. It was dangerous to those who mined and processed cinnabar, it caused shaking, loss of sense, and death. Data suggest that mercury was retorted from cinnabar and the workers were exposed to the toxic mercury fumes." Overexposure to mercury, mercurialism, was seen as an occupational disease to the ancient Romans: "Mining in the Spanish cinnabar mines of Almadén, southwest of Madrid, was regarded as being akin to a death sentence due to the shortened life expectancy of the miners, who were slaves or convicts."
Alkali metal obtained the same way: sulfuric acid is first used to dissolve the desired alkali metal ion and aluminium(III) ions from the ore (leaching), whereupon basic precipitation removes aluminium ions from the mixture by precipitating it as the hydroxide. The remaining insoluble alkali metal carbonate is then precipitated selectively; the salt is then dissolved in hydrochloric acid to produce the chloride. The result is then left to evaporate and the alkali metal can then be isolated. Lithium and sodium are typically isolated through electrolysis from their liquid chlorides, with calcium chloride typically added to lower the melting point of the mixture.