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Hokoite

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Formula:
Mn2+Mn3+2SiO6 · H2O
Colour:
black; dark brown
Lustre:
Vitreous, Resinous
Hardness:
3½
Specific Gravity:
3.354
Name:
Named after the type locality mine.
Inadequately described alteration product of other Mn silicates - rhodonite, braunite or tephroite. It is not on the IMA-CNMNC list of approved mineral species.

Originally described from Hohkoh mine (Hoko mine), Hiroshima prefecture, Chugoku region, Honshu Island, Japan.


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Unique IdentifiersHide

Mindat ID:
35858
Long-form identifier:
mindat:1:1:35858:7

Similar NamesHide

Hakite-(Cd)A valid IMA mineral speciesCu6(Cu4Cd2)Sb4Se12Se
Hakite-(Fe)A valid IMA mineral speciesCu6(Cu4Fe22+)Sb4Se12Se
Hakite-(Hg)A valid IMA mineral speciesCu6(Cu4Hg2)Sb4Se12Se
Hakite-(Zn)A valid IMA mineral speciesCu6(Cu4Zn2)Sb4Se12Se
HäggiteA valid IMA mineral species - grandfatheredV3+V4+O2(OH)3

IMA Classification of HokoiteHide

Classification of HokoiteHide

Strunz-mindat (2026):
9.HC.35

9 : SILICATES (Germanates)
H : Unclassified silicates
C : With Mn, Fe

Physical Properties of HokoiteHide

Lustre:
Vitreous, Resinous
Transparency:
Translucent
Colour:
Black; dark brown
Streak:
Brownish black
Hardness:
3½ on Mohs scale
Density:
3.354 g/cm3 (Measured)    

Optical Data of HokoiteHide

Type:
Isotropic

Chemistry of HokoiteHide

Mindat Formula:
Mn2+Mn3+2SiO6 · H2O
Element Weights:
Element% weight
Mn53.701 %
O36.491 %
Si9.151 %
H0.657 %

Calculated from ideal end-member formula.
Elements listed:
H, Mn, O, Si - search for minerals with similar chemistry

First Recorded Occurrence of HokoiteHide

Other Language Names for HokoiteHide

Dutch:Hokoiet
German:Hokoit

Related Minerals - Strunz-mindat GroupingHide

9.HC.05Erlianite(Fe,Mg)4(Fe,V)2Si6O15(OH,O)8Orth.
9.HC.10BostwickiteCaMn3+6Si3O16 · 7H2OOrth.
9.HC.20'Almbosite'Fe2+5Fe3+4V6+4Si3O27
9.HC.25'Aquacreptite (of Shepard)'Mg4Fe2Si6O19 · 8H2O with some Al2O3, or near
9.HC.30'Farallonite'2MgO · W2O5 · SiO2 · nH2O?Mon.
9.HC.40'Polyhydrite'

Other InformationHide

Special Storage/
Display Requirements:
On exposure to sunlight color changes to black
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

Internet Links for HokoiteHide

References for HokoiteHide

Localities for HokoiteHide

Showing 1 localities.

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.
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Locality ListHide

- This locality has map coordinates listed. - This locality has estimated coordinates. ⓘ - Click for references and further information on this occurrence. ? - Indicates mineral may be doubtful at this locality. - Good crystals or important locality for species. - World class for species or very significant. (TL) - Type Locality for a valid mineral species. (FRL) - First Recorded Locality for everything else (eg varieties). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).

All localities listed without proper references should be considered as questionable.
Japan (FRL)
 
  • Hiroshima Prefecture
Kinoshita (1927)
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