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Hollandite

Hollandite
General
Category Oxide minerals
Formula
(repeating unit)
Ba(Mn4+6Mn3+2)O16
Strunz classification 4.DK.05a
Dana classification 7.9.1.1
Crystal system Monoclinic
Crystal class Prismatic (2/m)
Space group Monoclinic
H-M symbol: (2/m)
Space group: I2/m
Identification
Color Silvery-grey to greyish
Cleavage Distinct / Good, Prismatic
Mohs scale hardness 4 to 6
Density 4.95

Hollandite (chemical formula: Ba(Mn4+6Mn3+2)O16) is an oxide mineral. It is the barium-manganese (III) endmember of the coronadite group.

A mineral, with the chemical composition BaMn4+6Fe3+2O16, that was first found in the Kajlidongri mine in the Jhabua district of Madhya Pradesh, India, had the name hollandite until it was reclassified as ferrihollandite by the International Mineralogical Association in 2012. Ferrihollandite is the barium-iron (III) endmember of the coronadite group.


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