METATORBERNITE

    Class : Phosphates, arsenates, vanadates
    Subclass : Uranyl phosphates
    Crystal system : Tetragonal
    Chemistry : Cu(UO2)2(PO4)2 8H2O
    Rarity : Quite common

Metatorbernite is a dehydration product of torbernite which forms by prolonged exposure to open air of this mineral, and which crystallizes directly above 75°C. Metatorbernite is almost systematically associated with torbernite (very often in pseudomorphs) in the oxidation zone of uranium and copper deposits, it is also occasionally found in low temperature hydrothermal veins. Its name comes from the Greek meta (after) and torbernite. It also closely resembles it in its habit, in square-shaped tabular crystals, often gathered in sprays or rosettes of 2 cm at most, and its pale green to dark green color. It is a uranium ore.

Main photo : Metatorbenite from Margabal, Aveyron, France

Metatorbenite on smoky quartz from Margabal, Aveyron, France
Tabular metatorbernite crystal from Margabal, Aveyron, France
Metatorbenite from Margabal, Aveyron, France
Metatorbernite from Bois Noirs, Puy-de-Dôme, France

Metatorbernite in the World

Metatorbernite shares most, if not all, torbernite deposits. The crystals are particularly remarkable in the mines of Congolese Katanga (Musonoï and Shinkolobwe), as well as in the English deposit of Gunnislake, near Tavistock (Cornwall). Metatorbernite is also present in the polymetallic uranium veins of the German Erzgebirge (Johanngeorenstadt, Schneeberg, etc...), in the Australian uranium deposits of South Alligator and the Canadian uranium deposits of Saskatchewan.

Metatorbernite in France

In France, beautiful crystals have been extracted from several uranium mines in the Massif Central : Bois Noirs (Puy-de-Dôme), L'Huis Jacques (Nièvre) and Margabal (Aveyron). It is reported in Chaméane (Puy-de-Dôme), Echassières (Allier), Montebras (Creuse), Mas d’Alary (Hérault), etc...

Twinning

Merohedral twinning is known (not visible externally on the crystals).

Fakes and treatments

No fakes recorded for this mineral species.


Hardness : 2.5
Density : 3.52 to 3.7
Fracture : Undetermined
Streak : Pale green

TP : Translucent to transparent
RI : 1.618 to 1.631
Birefringence : 0.004
Optical character : Uniaxial (+/-)
Pleochroism : Low
Fluorescence : None

Solubility : Acids

Magnetism : NoneRadioactivity : Very strong

ReCaptcha

This service is used to secure web forms of our website and required if you want to contact us. By accepting it you agree to Google's privacy policy: https://policies.google.com/privacy

Google Analytics

Google Analytics is a service used on our website that tracks, reports traffic and measures how users interact with our website content in order for us to improve it and provide better services.

Facebook

Our website allows you to like or share its content on Facebook social network. By activating and using it you agree to Facebook's privacy policy: https://www.facebook.com/policy/cookies/

YouTube

Integrated videos provided by YouTube are used on our website. By accepting to watch them you agree to Google's privacy policy: https://policies.google.com/privacy

Twitter

Integrated tweets and share services of Twitter are used on our website. By accepting and using these you agree to Twitter's privacy policy: https://help.twitter.com/en/rules-and-policies/twitter-cookies

PInterest

Our website allows you to share its content on PInterest social network. By activating and using it you agree to PInterest's privacy policy: https://policy.pinterest.com/en/privacy-policy/