Hokoite
A valid IMA mineral species - grandfathered - questionable
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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.
Type Locality:
Inadequately described alteration product of other Mn silicates - rhodonite, braunite or tephroite.
Originally described from Hohkoh mine (Hoko mine), Hiroshima prefecture, Chugoku region, Honshu Island, Japan.
Originally described from Hohkoh mine (Hoko mine), Hiroshima prefecture, Chugoku region, Honshu Island, Japan.
Unique Identifiers
Mindat ID:
35858
Long-form identifier:
mindat:1:1:35858:7
GUID
(UUID V4):
(UUID V4):
a54ab959-68f2-4c4e-808e-f991e383443e
IMA Classification of Hokoite
Approved, 'Grandfathered' (first described prior to 1959), Questionable
Classification of Hokoite
9.HC.35
9 : SILICATES (Germanates)
H : Unclassified silicates
C : With Mn, Fe
9 : SILICATES (Germanates)
H : Unclassified silicates
C : With Mn, Fe
Physical Properties of Hokoite
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 Hokoite
Type:
Isotropic
Chemistry of Hokoite
Mindat Formula:
Mn2+Mn3+2SiO6 · H2O
Elements listed:
Type Occurrence of Hokoite
Geological Setting of Type Material:
metasedimentary manganese ore
Associated Minerals at Type Locality:
Reference:
Kinoshita, K. (1927) A manganese silicate from the Hoko Mine, Prov' Alci' .Journal of the Geological Society, Tokyo, 34, 52-58
Related Minerals - Strunz-mindat Grouping
| 9.HC.05 | Erlianite | (Fe,Mg)4(Fe,V)2Si6O15(OH,O)8 |
| 9.HC.10 | Bostwickite | CaMn3+6Si3O16 · 7H2O |
| 9.HC.15 | Allophite | Mg8Al4Si5O24 · H2O |
| 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? |
| 9.HC.40 | Polyhydrite |
Other Information
Special Storage/
Display Requirements:
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 Hokoite
mindat.org URL:
https://www.mindat.org/min-35858.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
Mineral Dealers:
References for Hokoite
Reference List:
Localities for Hokoite
symbol to view information about a locality.
The Locality List
- 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).
All localities listed without proper references should be considered as questionable.
Japan (TL) | |
| Kinoshita (1927) |
