Psilomelane
Psilomelane
Published: June 2014
Modified: November 2021
The name Psilomelane was discredited as a distinct mineral variety but the name is still used as group name for hard black manganese oxides of which Romanechite and Hollandite are components. Psilomelane means smooth and black in Greek which aptly describes its appearance. It is often found in botryoidal masses with submetallic luster.
General Information
Common Name
Psilomelane
Species
Psilomelane
Transparency
Opaque
Dispersion
Strength: None
Refractive Index
Over The Limit 2.110-2.260
Optic Character
NA
Optic Sign
NA
Pleochroism
None
Hardness
5-6
Streak
Brownish Black To Black, Shiny
Toughness
Poor
Inclusions
Psilomelane is sometimes botryoidal and might have pyrolusite bands or swirls.
Luster
Dull, Submetallic, Metallic
Fracture
Uneven
Cleavage
None
Chemical Name
manganese oxide
Chemical Formula
(Ba, H2O2)Mn5O10
Crystal System
Monoclinic
Chemistry Classification
Oxide
Psilomelane Colors
-
Black
Countries of Origin
Russian Federation; Sweden; Belgium; Unknown; China; United States of America; Mexico; France; Germany; India
Care
Normal care