CUBANITE

    Class : Sulfides and sulfosalts
    Subclass : Sulfides
    Crystal system : Orthorhombic
    Chemistry : CuFe2S3
    Rarity : Uncommon

Cubanite is an iron and copper sulphide which has a predilection for high temperature hydrothermal deposits : pyrrhotite - löllingite - arsenopyrite veins, pyrrhotite skarns and other pyrometasomatic deposits, chalcopyrite - pentlandite magmatic deposits of mafic complexes. His name refers to his country of discovery : Cuba. Cubanite generally occurs in fine oriented lamellae in chalcopyrite : these exsolutions become individualized when the temperature of the hydrothermal fluids drops between 200°C and 210°C; sometimes, it forms millimetric acicular crystals, rarely thick or striated tabular crystals reaching 3 cm and then commonly showing complex twins. The color is bronze to brass yellow. It is a fairly strongly magnetic mineral. It is a very accessory ore of copper.

Main photo : Twinned cubanite from Henderson Mine, Jamésie, Québec, Canada © Tomasz Praszkier

Twinned cubanite from Henderson Mine, Jamésie, Canada © Chris Stefano
Twinned cubanite from Henderson Mine, Jamésie, Canada © John A. Jaszczak
Cubanite from Samson Mine, St-Andreasberg, Germany © Stephan Wolfsried
Cubanite from Ste-Marie-aux-Mines, Haut-Rhin, France © Thierry Brunsperger

Cubanite in the World

Due to the diversity of its deposits, cubanite is a relatively common mineral, but often microscopic in size. Superb centimeter-sized crystals, the most beautiful known, come from Chibougamau (Quebec, Canada); beautiful specimens were also extracted from the copper and nickel mines of Sudbury (Ontario, Canada). The Morro Velho gold deposit (Minas Gerais, Brazil) is famous for its free cubanite crystals in gold-bearing quartz geodes.

Cryptomelane in France

In France, cubanite is known in radiated aggregates of microscopic crystals in the galena of the Saint-Maudé vein, near Baud (Morbihan) as well as in many Breton deposits, but also in Barlet (Haute-Loire), in Chessy (Rhône), in St-Jean-de-Maurienne (Savoie), in Ste-Marie-aux-Mines (Haut-Rhin), etc...

Twinning

A twin is known on {110} forming sets of 2, 4 or 6 crystals.

Fakes and treatments

No fakes listed for this mineral species.


Hardness : 3.5
Density : 4.03 to 4.18
Fracture : Conchoidal
Streak : Gray-black

TP : Opaque
RI : -
Birefringence : -
Optical character : -
Pleochroism : None
Fluorescence : None

Solubility : Nitric acid


Magnetism : Ferromagnetic
Radioactivity : None

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/