ROMANECHITE

    Class : Oxides and hydroxides
    Subclass : Oxides
    Crystal system : Monoclinic
    Chemistry : (Ba,H2O)2Mn5O10
    Rarity : Quite common

Romanechite is part of the psilomelane group, which also includes hollandite and coronadite. The general term "psilomelane" in the literature is very frequently romanechite to the point that some authors practically consider these two terms as synonyms... It is indeed difficult to formally identify without advanced analytical means. It is a relatively common secondary mineral in the oxidation zone of manganese deposits, often associated with manganese carbonates and silicates, sometimes with baryte and fluorite. Its name comes from its discovery location : Romanèche-Thorins (Saône-et-Loire, France). Romanechite occurs almost exclusively in compact botryoidal masses with fibroradiated textures, iron black in color, and submetallic to matte luster. It is an important manganese ore.

Main photo : Romanechite from Haiti mine, Cabezo de San Ginés, Murcia, Spain © Juan González

Romanechite in the World

Romanechite forms particularly spectacular masses at Schneeberg (Saxony, Germany), as well as on other German deposits. It is a common mineral in manganese deposits in the United States, Australia, Ukraine (Nikopol) and India.

Romanechite in France

In France, botryoidal masses of romanechite, composed of fibroradiated spherules of 15 mm in diameter are known at Romanèche (Saône-et-Loire), its locality of definition. It is also known in Saphoz (Haute-Saône) and Ste-Marie-aux-Mines (Haut-Rhin).

Right photo : Romanèchite from Romanèche-Thorins, Saône-et-Loire, France © Juan Miguel Segura

Twinning

Twins are known on acicular crystals.

Fakes and treatments

No fakes listed for this mineral species.


Hardness : 5 to 6
Density : 4
Fracture : Undetermined
Streak : Black

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

Solubility : -

Magnetism : NoneRadioactivity : None