SPANGOLITE

    Class : Sulfates, chromates, molybdates
    Subclass : Hydrated sulfates
    Crystal system : Trigonal
    Chemistry : Cu6AlSO4(OH)12Cl 3H2O
    Rarity : Fairly common

Spangolite is a secondary copper and aluminum sulfate present in the oxidation zone of copper deposits, often associated with malachite, azurite and brochantite. It is also found in some industrial slags. It was named in honor of Norman Spang who provided the definition samples. Spangolite is tabular crystals, sometimes stocky prismatic, frequently hemimorphic, of bluish-green, emerald green or blue color.

Main photo : Spangolite, azurite and malachite from Aranzazú Mine, Zacatecas, Mexico © Peter Megaw

Spangolite from Mex-Tex Mine, Bingham, New-Mexico, USA © Henk Smeets
Spangolite from Mex-Tex Mine, Bingham, New-Mexico, USA © Henk Smeets
Spangolite from Mex-Tex Mine, Bingham, New-Mexico, USA © Gianfranco Ciccolini
Spangolite from Fontana Rossa, Haute-Corse, France © Yannick Vessely

Spangolite in the World

Magnificent 3 cm crystals, the most beautiful known, come from Bisbee (Arizona). Other superb crystals of smaller dimensions come from the Blanchard mine near Bingham (New Mexico), from Tintic Junction (Utah) and from Majuba Hill (Nevada). Beautiful crystals are also reported at Aranzazú Mine (Mexico).

Spangolite in France

In France, spangolite has been discovered in the superficial parts of several copper deposits ; the most beautiful come from Fontana Rossa (Corsica) but it is also described at Cap Garonne (Var), at Kaymar (Aveyron), at Trébas (Tarn) and in the slags of Crozet (Loire).

Twinning

Twinning is known but rare on {0001}.

Fakes and treatments

No fakes listed for this mineral species.


Hardness : 3
Density : 3.13 to 3.14
Fracture : Conchoidal
Streak : Pale green

TP : Translucent to transparent
RI : 1.627 to 1.687
Birefringence : 0.053
Optical character : Uniaxial -
Pleochroism : Low
Fluorescence : None

Solubility : Acids

Magnetism : NoneRadioactivity : None