• Iodure de Mercure
  • Iodquecksilber or mercuric
  • Hoppingit
  • Mercury ( II) iodide

Coccinit is a very rarely occurring mineral from the mineral class of halides. It crystallizes in the tetragonal crystal system with the composition Hg2 I2, so is chemically a mercury (II ) iodide.

Coccinit developed only millimeter-sized crystals and powdery coatings or crusts of scarlet or orange-red to brown in color with orange red line color.

Special Features

The mineral is very toxic, direct contact should be avoided.

Etymology and history

Coccinit was first discovered in Casas Viejas in Mexico and described in 1829 by Del Rio as iodure de Mercure ( German: Iodmercur or Iodquecksilber or mercuric iodide ).

His final name was the mineral in 1845 by Wilhelm von Haidinger, who named it based on its color after the Latin word coccineus for " scarlet ".


In the now outdated but still in use 8th edition of the mineral classification by Strunz the Coccinit belonged to the department of a "Simple halides ," where he along with fluorite, Frankdicksonit, Gagarinit - (Y), Gagarinit - (Ce) (formerly Zajacit ( ce) ), Håleniusit - (La), Laurelit and Tveitit - (Y) the " fluorite series" with the system no. III/A.08 formed.

The 9th edition valid since 2001 and of the International Mineralogical Association (IMA ) used the Strunz'schen Mineral classification assigns the Coccinit in the newly defined division of a "Simple halides, without H2O" one. This department is also further subdivided by the molar ratio of metal (M) to professionals involved halide ( X), so that the mineral according to its composition in the subsection "M: X = 1: 2 ," is to find where it is the only member of the untitled set 3.AB.10 forms.

The mainly common in English-speaking classification of minerals according to Dana assigns the Coccinit in the department of " halides ". Here he is with Cotunnit and Hydrophilit in the " Cotunnitgruppe " with the system no. 09:02:07 to find " water clear and hydrated halides of the formula AX2 " within the subdivision of.

Education and Locations

Due to its rarity, so far no detailed statements about the formation conditions of Coccinit could be made.

So far (as of 2012) was the mineral except at its type locality Casas Viejas in Mexico still at Broken Hill (New South Wales) in Australia and in the pits " oven " and " Carolina " on Moschellandsberg ( Rhineland -Palatinate ) and open pit Lichtenberg ( Thuringia, see also deposit description when bismuth AG) in Germany.

Crystal structure

Coccinit crystallizes in the tetragonal crystal system in space group P42/nmc, the lattice parameters a = 4.38 Å and c = 12.41 Å and two formula units per unit cell.