STOLZITE
Class : Sulphates, chromates, molybdates
Subclass : Tungstates
Crystal system : Tetragonal
Chemistry : PbWO4
Rarity : Rare
Stolzite is a rare oxidation mineral of lead deposits containing tungsten, and tin-tungsten deposits with accessory galena. It forms a discontinuous isomorphic series with wulfenite, the intermediate term being chillagite. It owes its name to Joseph Alexander Stolz, who was first interested in this mineral. Like wulfenite, stolzite frequently occurs in thick, flattened square tablets, more rarely in more or less acute octahedra. Its luster is adamantine and its color variablen: yellowish brown to greyish brown, sometimes red to orange. Often confused with wulfenite, although its colors are more vivid, it was recently considered very rare. It is a mineral sought after by collectors.
Stolzite in the World
Stolzite in France
The largest crystals in the world come from the small lead mine in Sainte-Lucie (Lozère, France) : the brown-yellow tabular specimens measure up to 6 cm across. The kaolin quarries at Echassières also produced millimetric crystals.
Twinning
Stolzite has no twinned crystals known.
Fakes and scams
No scam known for this mineral.
Hardness : 2.5 to 3
Density : 8.34
Fracture : Irregular to conchoidal
Trace : White
TP : Opaque to transparent
RI : 2.19 to 2.27
Birefringence : 0,090
Optical character : Uniaxial -
Pleochroism : Visible
Fluorescence : White-green
Solubility : Hydrochloric acid
Magnetism : None
Radioactivity : None