Coccinite

Coccinite is a rare mercury iodide mineral with chemical formula of HgI₂, mercury(II) iodide. in addition to its discovery locality of Casas Viejas, Mexico, it has also been reported from Broken Hill, New South Wales, and from a uranium mine in Thuringia and old mercury workings in the Rhineland-Palatinate in Germany. At the Thuringia deposit the mineral occurs as a sublimation product resulting from fires associated with pyrite bearing, graptolitic slate.