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
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