SVANBERGITE

    Class : Sulfates, chromates, molybdates
    Subclass : Anhydrous sulfates
    Crystal system : Trigonal
    Chemistry : SrAl3(PO4)(SO4)(OH)6
    Rarity : Uncommon


Svanbergite is a complex phosphate in which PO4 groups are substituted by SO4 sulfate groups. It is a late alteration mineral that occurs in a variety of contexts : aluminous metamorphic rocks with kyanite or andalusite, bauxite deposits, alteration aureoles of metalliferous deposits (often associated with pyrophyllite), replacement of apatite in carbonatites, or surface oxidation zone of iron deposits. It was named in honor of Professor of Mineralogy Mars Fredrik Svanberg of Uppsala University (Sweden). Svanbergite forms rhombohedral or pseudocubic crystals up to 5 mm in size, colorless or cream to cream-brown, pink or red-brown.

Main photo : Svanbergite from Mount Brussilof mine, British Columbia, Canada © Chris Stefano

Svanbergite from Pomba pit, Serra das Éguas, Brumado, Bahia, Brazil © Luigi Chiappino
Svanbergite from Mount Brussilof mine, Canada © Tony Peterson
Svanbergite pseudomorph after tourmaline from Pomba pit, Brumado, Brazil © Rob Lavinsky
Svanbergite from Västanå Iron Mine, Sweden © Bertil Otter

Svenbergite in the World

Svanbergite is not rare. Among its most characteristic deposits are the andalusite quarry of Dover (Nevada), and the mines of Champion and Blue Bird in California. In Sweden, svanbergite is well represented in the iron mine of Västana and Horrsjöberg, its type locality, where the crystals can reach a centimeter. Stable in alluvium, it is preserved in the diamondiferous gravels of Paraguaçu (Bahia, Brazil).

Svanbergite in France

In France, svanbergite is known in the alteration aureole of the sulfidic mass of Chizeuil (Saône-et-Loire), associated with pyrophyllite.

Twinning

No twinning known for this mineral species. Svanbergite pseudomorph after tourmaline are known in Brazil.

Fakes and treatments

No fakes listed for this mineral species.



Hardness : 5
Density : 3.2 to 3.24
Fracture : Undetermined
Streak : White


TP : Translucent
RI : 1.631 to 1.649
Birefringence : 0.015
Optical character : Uniaxial +
Pleochroism : None
Fluorescence : None


Solubility : Insoluble

Magnetism : NoneRadioactivity : None