DEVILLITE

    Class : Sulfates, chromates, molybdates
    Subclass : Hydrated sulfates
    Crystal system : Monoclinic
    Chemistry : CaCu4(SO4)2(OH)6 3H2O
    Rarity : Uncommon

Devilline (or devillite) is a hydrated sulfate from the oxidation zone of copper deposits. It is also found in neo-formation in slags. It was named in honor of the French chemist Henri Etienne Sainte-Claire Deville, inventor of the first industrial aluminum manufacturing process. It forms six-sided lamellar to acicular crystals, united in rosettes or encrustations, white in color or various shades of green and blue.

Main photo : Devilline from Spania Dolina, Banská Bystrica, Slovakia © Martin Stevco

Devilline of Altáró, Nagybörzsöny, Szob, Pest County, Hungary © Bela Feher
Devilline du Crozet, Loire, France © Pascal Chollet
Devilline from the Couloumier Mine, Ariège, France © Enrico Bonacina
Devilline on Crozet slag, Loire, France © Yannick Vessely

Devilline in the World

The best samples of devilline are lamellar crystals grouped in rosettes exceeding 4 cm from Spania Dolina (Slovakia). Interesting specimens are also known from Warren (Arizona). It is reported at Laurion (Greece), at the Clara Mine (Germany), etc...

Devilline in France

In France, devilline is present in Vezzani (Haute-Corse) where it is associated with spangolite and builds centimeter-sized stalactites. It is also found in microcrystals at the Couloumier mine (Ariège), at Echassières (Allier), at Chessy (Rhône), at Ste-Marie-aux-Mines and Steinbach (Haut-Rhin), at St-Yrieix-la-Perche (Haute-Vienne), in Salsigne (Aude), in Villefranche-de-Rouergue (Aveyron), in Malines (Gard), in Cap Garonne (Var), in Crozet (Loire) as well as in the slag of Poullaouen (Finistère).

Twinning

A twin is known on {010}.

Fakes and treatments

No fakes listed for this mineral species.


Hardness : 2.5
Density : 3.08 to 3.13
Fracture : Undetermined
Streak : Light green

TP : Transparent
RI : 1.585 to 1.660
Birefringence : 0.075
Optical character : Biaxial -
Pleochroism : Visible
Fluorescence : None

Solubility : Nitric acid


Magnetism : None
Radioactivity : None