SLAVIKITE

    Class : Sulfates, chromates, molybdates
    Subclass : Hydrated sulfates
    Crystal system : Trigonal
    Chemistry : NaMg2Fe5(SO4)7(OH)6 33H2O
    Rarity : Rare to very rare


Slavikite is a rare magnesium and iron sulfate, formed by alteration of iron sulfides. It is associated with other iron sulfates (copiapite, melanterite, jarosite, etc...), resulting like it from precipitation from "natural" sulfuric acid formed by reaction of surface water with iron sulfides. It is a mineral of the superficial oxidation zones of sulfide deposits and pyritic rocks. It was named in honor of the Czech mineralogist Frantisek Slavik, Professor at Charles University in Prague. Slavikite forms tiny, scaly, tabular crystals, often agglomerated in encrustations, of a yellowish green to light olive-gray hue.

Main photo : Slavikite from Gérgal, Almería, Spain © Christophe Boutry

Slavikite in the World

Slavikite is a rare secondary mineral that is known in good samples in the Skrivany hydrothermal vein (Czech Republic) where it forms at the expense of pyritic schists, associated with halotrichite and pickeringite. Slavikite is also reported in Spain, Slovakia, Norway, Austria and Belgium.


Slavikite  in France

In France, slavikite is known at Kaymar (Aveyron).

Right photo : Slavikite from Le Kaymar, Aveyron, France © Maggie Wilson

Twinning

No twinning known for this mineral species.

Fakes and treatments

No fakes listed for this mineral species.



Hardness : 3.5
Density : 1.90 to 1.99
Fracture : Undetermined
Streak : Yellow


TP : Translucent to transparent
RI : 1.495 to 1.537
Birefringence : 0.036
Optical character : Biaxial +
Pleochroism : Visible
Fluorescence : None


Solubility : -

Magnetism : NoneRadioactivity : None