Iltisite

General Information:
 Chemical Formula:
HgSAg(Cl,Br)
 Composition:
(Molecular Weight = 387.09 gm)
Silver 27.87 % Ag
Mercury 51.82 % Hg
Sulfur 8.28 % S 
Bromine 5.16 % Br
Chlorine 6.87 % Cl
 Empirical Formula:
HgSAgCl0.75Br0.25
 Environment:
In small cavities in conglomerate. A hexagonal polymorph of capgaronnite.
 IMA Status:
Approved IMA (Dana # Added)
 Locality:
The Cap Garonne mine, near Le Pradet, Var, France.
 Name Origin:
For Antoine Iltis (1942-), who found the mineral.
Physical Properties:
 Cleavage:
[001] Perfect
 Color:
red or brownish red.
 Density:
6.59
 Diaphaniety:
Translucent
 Habits:
Platy - Sheet forms (e.g. micas)., Disseminated - Occurs in small, distinct particles dispersed in matrix.,
 Luminescence:
Non-fluorescent.
 Luster:
Adamantine
 Streak:
red
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