CHILLAGITE
Class : Sulfates, chromates, molybdates
Subclass : Molybdates
Crystal system : Tetragonal
Chemistry : PbMoO4
Rarity : Very rare
Chillagite is a tungstitious variety of wulfenite, individualized because it has a chemical composition intermediate between those of stolzite and wulfenite, the result of a partial replacement of molybdenum by tungsten. Its name comes from its locality of discovery : Chillagoe (Australia). It is a rare variety, whose morphological and gitotomological characteristics are those of wulfenite sensu stricto : thin tablets of square section, of a less bright color than the latter yellow, pale yellow-orange, gray or black known in the oxidation zone of lead-molybdenum deposits in an arid climate. It is a very accessory molybdenum ore and a variety little known to collectors.
Main photo : Chillagite from Tsumeb Mine, Namibia © Neal Luppescu
Chillagite in the World
Chillagite in France
This mineral is not present in the French underground.
Twinning and special forms
No known twin for this mineral variety.
Hardness : 2.5 to 3
Density : 6.5 to 7
Fracture : Irregular to subconchoidal
Trace : White, white-yellow
TP : Translucent to transparent
IR : 2.283 to 2.405
Birefringence : 0.122
Optical character : Uniaxial -
Pleochroism : Weak
Fluorescence : None
Solubility : Sulfuric acid
Magnetism : None
Radioactivity : None