KASOLITE

    Class : Silicates
    Subclass : Nesosilicates
    Crystal system : Monoclinic
    Chemistry : Pb(UO2)SiO4 H2O
    Rarity : Quite common

Kasolite is a fairly common secondary silicate from the oxidation zone of uranium deposits. Its name comes from its place of discovery : Shinkolobwe near Kasolo (Democratic Republic of Congo). Kasolite appears in small elongated sockets, sometimes flattened, frequently grouped in rosettes, spherules or encrustations, of a beautiful orange to orange-red hue (rarely grayish green or canary yellow). It is an accessory uranium ore.

Main photo : Kasolite and torbernite from Musonoï, Katanga, Democratic Republic of Congo © Frédéric Hède

Kasolite from Musonoï, Katanga, Democratic Republic of Congo © Matteo Chinellato
Kasolite from Zálesí, Javorník, Czech Republic © Bohuslav Bures
Kasolite from Echassière, Allier, France © Michael Förch
Kasolite from La Faye Mine, Grury, Saône-et-Loire, France © Christopher O'Neill

Kasolite in the World

Kasolite is found in the uranium deposits of Congolese Katanga (Musonoï and Shinkolobwe) which provided magnificent radiated spherolitic aggregates made up of elongated millimetric crystals with lanceolate ends, orange to yellow in color.

Kasolite in France

In France, the La Faye mine near Grury (Saône-et-Loire) produced 2 mm geodic prisms, flattened needles grouped in rosettes, and tiny spherolites. But it is to the Kerségalec mine near Lignol (Morbihan) that we owe the best French samples : encrustations of orange radiate spherules exceeding 5 mm in diameter. It is also reported in Margnac (Haute-Vienne), Echassières (Allier), Lachaux (Puy-de-Dôme) and St-Priest-la-Prugne (Loire).

Twinning

No twin known for this mineral species.

Fakes and treatments

No fakes recorded for this mineral species.


Hardness : 4 to 5
Density : 5.83 to 6.5
Fracture : Undeterminated
Streak : Pale yellow

TP : Opaque to transparent
RI : 1.890 to 1.950
Birefringence : 0.060
Optical character : Biaxial +
Pleochroism : Low
Fluorescence : None

Solubility : Acids

Magnetism : NoneRadioactivity : Strong