Mindat Logo

Todorokite

Formula:
(Mn,Mg,Ca,Ba,K,Na)
 
2
Mn
 
3
O
 
12
·3H
 
2
O
System:MonoclinicColour:Purplish gray, brown to ...
Hardness:
Name:Named after its discovery locality, the Todoroki Mine, Hokkaido, Japan.


Cryptomelane Group.

Classification of Todorokite

IMA status:Approved
Strunz 8th edition ID:4/D.09-10
Nickel-Strunz 10th (pending) edition ID:4.DK.10

4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
D : Metal: Oxygen = 1:2 and similar
K : With large (+- medium-sized) cations; tunnel structures
Dana 8th edition ID:7.8.1.1

7 : MULTIPLE OXIDES
8 : AB3X7
Hey's CIM Ref.:7.4.19

7 : Oxides and Hydroxides
4 : Oxides of Be, Mg and the alkaline earths
mindat.org URL:http://www.mindat.org/min-3988.html
Please feel free to link to this page.

Type Occurrence of Todorokite

Type Locality:Todoroki mine, Shiribeshi Province, Hokkaido Island, Japan
Year of Discovery:1934

Physical Properties of Todorokite

Lustre:Metallic
Diaphaneity (Transparency):Opaque
Colour:Purplish gray, brown to black; brown in transmitted light
Hardness (Mohs):
Cleavage:Perfect
{100} and {010} perfect.

Crystallography of Todorokite

Crystal System:Monoclinic
Class (H-M):2/m - Prismatic
Space Group:P2/m (P1 1 2/m) [P2/m] {P1 2/m 1}
Cell Parameters:a = 9.75Å, b = 2.84Å, c = 9.59Å
β = 90°
Ratio:a:b:c = 3.433 : 1 : 3.377
Unit Cell Volume:V 265.55 ų (Calculated from Unit Cell)
Morphology:Spongy banded and reniform aggregates composed of minute lathlike crystals. Crystals flattened {010} and elongated [001] with terminal edges inclined about 60° and 70° to [01].
Twinning:Contact twins with c ^ ć about 60°.
X-Ray Powder Diffraction:
d-spacingIntensity
9.65 (100)
7.02 (40)
4.82 (70)
4.48 (70)
3.20 (10)
3.07 (40)
2.75 (10)
2.46 (40)
2.42 (10)
2.35 (40)
2.28 (10)
2.20 (5)
2.13 (10)
1.98 (10)
1.91 (5)
1.77 (10)
Comments:JCPDS 18-1411

Chemical Properties of Todorokite

Formula:
(Mn,Mg,Ca,Ba,K,Na)
 
2
Mn
 
3
O
 
12
·3H
 
2
O
Essential elements:H, Mn, O
All elements listed in formula:Ba, Ca, H, K, Mg, Mn, Na, O
Common Impurities:Ba,K,Na

Relationship of Todorokite to other Species

Related Minerals - Nickel-Strunz Grouping):
4.DK.05Akaganeite
β-Fe
3+
 
O(OH,Cl)
4.DK.05Ankangite
Ba(Ti,V
3+
 
,Cr)
 
8
O
 
16
4.DK.05Coronadite
Pb(Mn,Mn)
 
8
O
 
16
4.DK.05Hollandite
Ba(Mn
4+
 
,Mn
2+
 
)
 
8
O
 
16
4.DK.05Manjiroite
(Na,K)Mn
 
8
O
 
16
·nH
 
2
O
4.DK.05Mannardite
Ba
 
x
Ti
 
8-2x
V
 
2x
O
 
16
·2-xH
 
2
O
4.DK.05Priderite
(K,Ba)(Ti,Fe)
 
8
O
 
16
4.DK.05Redledgeite
Ba
 
x
([Cr,Fe,V]
3+
2x
Ti
 
8-2x
)O
 
16
4.DK.05Henrymeyerite
BaFe
2+
 
Ti
 
7
O
 
16
4.DK.10Cryptomelane
K(Mn
4+
 
,Mn
2+
 
)
 
8
O
 
16
4.DK.10Romanèchite
(Ba,H
 
2
O)
 
2
Mn
 
5
O
 
10
4.DK.10Strontiomelane
SrMn
4+
6
Mn
3+
2
O
 
16
Related Minerals - Hey's Index Grouping:
7.4.1Bromellite
BeO
7.4.2Behoite
Be(OH)
 
2
7.4.3Clinobehoite
Be(OH)
 
2
7.4.4Chrysoberyl
BeAl
 
2
O
 
4
7.4.5Magnesiotaaffeite-2N’2S
Mg
 
3
Al
 
8
BeO
 
16
7.4.6Magnesiotaaffeite-6N’3S
(Mg,Fe,Zn)
 
2
Al
 
6
BeO
 
12
7.4.7Periclase
MgO
7.4.8Brucite
Mg(OH)
 
2
7.4.9Spinel
MgAl
 
2
O
 
4
7.4.10Meixnerite
Mg
 
6
Al
 
2
(OH)
 
18
·4H
 
2
O
7.4.11Lime
CaO
7.4.12Portlandite
Ca(OH)
 
2
7.4.13Mayenite
Ca
 
12
Al
 
14
O
 
33
7.4.14Hydrocalumite
Ca
 
2
Al(OH)
 
7
·2H
 
2
O
7.4.15Marokite
CaMn
 
2
O
 
4
7.4.16Ranciéite
(Ca,Mn)Mn
 
4
O
 
9
·3H
 
2
O
7.4.17Hollandite
Ba(Mn
4+
 
,Mn
2+
 
)
 
8
O
 
16
7.4.18Romanèchite
(Ba,H
 
2
O)
 
2
Mn
 
5
O
 
10

Other Names for Todorokite

German names:
Todorokit
Japanese names:
轟石
Russian names:
Тодорокит
Spanish names:
Todorokita

Other Information

Health Warning:No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

References for Todorokite

Reference List:Journal of the Faculty of Science, Hokkaido University (1934), series 4, 2, 289-297.

American Mineralogist (1935): 20: 678.

American Mineralogist (1960): 45: 1167-1184.

American Mineralogist (1979): 64: 1333-1334.

Golden, D.C., C.C. Chen, and J.B. Dixon (1987), Transformation of birnessite to buserite, todorokite, and manganite under mild hydrothermal treatment: Clays and Clay Minerals: 35: 271-280.

American Mineralogist (1988): 73: 861-869.

Post, J. E., Heaney, P. J., Hanson, J. (2003) - Synchroton X-ray diffraction study of the structure and dehydratation behavior of todorokite. American Mineralogist: 88: 142-150.

Internet Links for Todorokite

Search Engines:
  • Look for Todorokite on Google
  • Look for Todorokite images on Google
  • External Links:
  • Look for Todorokite on Webmineral
  • Look for Todorokite on Athena Mineralogy
  • Look for Todorokite on Wikipedia
  • Look for Todorokite on Mineralien Atlas
  • Raman and XRD data at RRUFF project
  • American Mineralogist Crystal Structure Database
  • Search for Todorokite in the Natural History Museum (London) online catalogue
  • Todorokite details from Handbook of Mineralogy (PDF)
  • Mineral Dealers:
  • Wright's Rock Shop - excellent mineral specimens since 1970
  • The Arkenstone - Fine Minerals
  • Buy Fine Minerals from mineralsweb.com
  • rare and unusual minerals mainly crystallized
  • Fabre Minerals - search for Todorokite specimens
  • Search for Todorokite at Thames Valley Minerals
  • Lapis Mineral Magazin
  • Search for Todorokite on minvision.com
  • Mineral Classics - Worldwide Collector Quality Minerals and Gems
  • Find Todorokite on www.crystalclassics.co.uk
  • Buy fine minerals and gemstones from Pala International
  • Buy Minerals and Crystals from Crystalarium.com
  • Jobs:
  • Mining & Geology Jobs
  • Page Sponsor

    Sponsorship:This page is currently not sponsored. Click here to find out how you can sponsor this page.

    Localities for Todorokite

    The 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.
    These maps work faster with Firefox!
    Mineral and/or Locality
    Google
     
    www.mindat.org Web
    Copyright © Jolyon & Ida Ralph 1993-2008. Site Map. Locality, mineral & photograph data are the copyright of the individuals who submitted them.Further information contact the Site hosted & developed by Jolyon Ralph. Mindat.org is an online information resource dedicated to providing free mineralogical information to all. Mindat relies on the contributions of hundreds of members and supporters. If you would like to add information to improve the quality of our database, then click here to register.