Editing Psilomelane (section)

{{Short description|Hard black manganese oxides (romanechite, mainly)}}
{{No footnotes|date=February 2023}}
{{Infobox mineral
| name        = Psilomelane
| category    = [[Oxide minerals]]
| boxwidth    = 
| boxbgcolor  = 
| image       = Mineraly.sk - psilomelan.jpg
| imagesize   = 260px
| caption     = 
| formula     = General formula:<br>{{chem2|Ba(Mn(2+))(Mn(4+))8O16(OH)4}}, or as {{chem2|(Ba,H2O)2Mn5O10}}<br>Barium manganese oxide hydroxide
| molweight   = 590.03 g/mol
| system      = [[Monoclinic]]
| color       = Black with gray [[pyrolusite]] bands
| habit       = [[Botryoidal]], [[mammillary]], [[Crystal habit#List of crystal habits|reniform]]
| twinning    = 
| cleavage    = None
| fracture    = [[Conchoidal]] and uneven
| mohs        = 5.0 – 6.0
| luster      = Sub-metallic, dull
| polish      = Vitreous to [[Lustre (mineralogy)#Adamantine lustre|subadamantine]]
| refractive  = 
| opticalprop = 
| birefringence = 
| pleochroism = 
| streak      = Brownish black
| gravity     = 3.7 – 4.7
| melt        = 
| fusibility  = 
| diagnostic  = 
| solubility  = in [[hydrochloric acid]]
| diaphaneity = Opaque
| other       = Hard black [[manganese oxide]]s such as [[hollandite]] and [[romanechite]] 
}}

'''Psilomelane''' is a group name for hard black [[manganese oxide]]s including [[hollandite]] and [[romanechite]]. Psilomelane consists of hydrous [[manganese]] oxide with variable amounts of [[barium]] and [[potassium]]. Psilomelane is erroneously, and uncommonly, known as '''black hematite''', despite not being related to true [[hematite]], which is an iron oxide.