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Amakinite

A valid IMA mineral species
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About AmakiniteHide

Formula:
Fe2+(OH)2
Colour:
Pale green to yellow-green; rapidly turns brown when exposed to air, due to formation of Fe(OH)3
Hardness:
3½ - 4
Specific Gravity:
2.925 - 2.98
Crystal System:
Trigonal
Member of:
Name:
For the Amakin Expedition, which prospected the Yakutian diamond deposits.
This page provides mineralogical data about Amakinite.


Unique IdentifiersHide

Mindat ID:
180
Long-form identifier:
mindat:1:1:180:1

IMA Classification of AmakiniteHide

Classification of AmakiniteHide

4.FE.05

4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
F : Hydroxides (without V or U)
E : Hydroxides with OH, without H2O; sheets of edge-sharing octahedra
6.2.1.2

6 : HYDROXIDES AND OXIDES CONTAINING HYDROXYL
2 : X(OH)2
7.20.10

7 : Oxides and Hydroxides
20 : Oxides of Fe

Mineral SymbolsHide

As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.

Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.

SymbolSourceReference for Standard
AmkIMA–CNMNCWarr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43
AmkWhitney & Evans (2010)Whitney, D.L. and Evans, B.W. (2010) Abbreviations for names of rock-forming minerals. American Mineralogist, 95, 185–187 doi:10.2138/am.2010.3371

Physical Properties of AmakiniteHide

Transparency:
Translucent
Colour:
Pale green to yellow-green; rapidly turns brown when exposed to air, due to formation of Fe(OH)3
Hardness:
3½ - 4 on Mohs scale
Cleavage:
Poor/Indistinct
observed in some grains
Fracture:
Irregular/Uneven
Density:
2.925 - 2.98 g/cm3 (Measured)    2.74 g/cm3 (Calculated)

Optical Data of AmakiniteHide

Type:
Uniaxial (+)
RI values:
nω = 1.707(2) nε = 1.722(2)
Max. Birefringence:
δ = 0.015
Based on recorded range of RI values above.

Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.

Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.

Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.

Surface Relief:
Moderate

Chemistry of AmakiniteHide

Mindat Formula:
Fe2+(OH)2
Element Weights:
Element% weight
Fe62.147 %
O35.610 %
H2.243 %

Calculated from ideal end-member formula.

Crystallography of AmakiniteHide

Crystal System:
Trigonal
Cell Parameters:
a = 6.917(3) Å, c = 14.52(1) Å
Ratio:
a:c = 1 : 2.099
Unit Cell V:
601.63 ų (Calculated from Unit Cell)
Z:
12
Morphology:
Rhombohedra {1011}, modified by {1012}, {1014}, {1123}, {2025} and {0001} to 2 cm; typically in irregular grains.
Comment:
Point Group: 3 2/m, 3m, or 32.; Space Group: R3m, R3m, or R32.

Crystal StructureHide

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IDSpeciesReferenceLinkYearLocalityPressure (GPa)Temp (K)
0011783AmakiniteWyckoff R W G (1963) Second edition. Interscience Publishers, New York, New York Crystal Structures 1 239-44419630293
CIF Raw Data - click here to close

X-Ray Powder DiffractionHide

Geological EnvironmentHide

Paragenetic Mode(s):
Paragenetic ModeEarliest Age (Ga)
Stage 2: Planetesimal differentiation and alteration4.566-4.550
6 : Secondary asteroid phases4.566-4.560

Type Occurrence of AmakiniteHide

General Appearance of Type Material:
rhombohedra to 1.5 cm; typically in irregular grains
Place of Conservation of Type Material:
A.E. Fersman Mineralogical Museum, Academy of Sciences, Moscow, Russia, 69547.
Geological Setting of Type Material:
in a drill core, in thin veins and pockets in kimberlite
Associated Minerals at Type Locality:

Other Language Names for AmakiniteHide

Dutch:Amakiniet
French:Amakinite
German:Amakinit
Norwegian:Amakinitt
Simplified Chinese:羟铁矿
Spanish:Amakinita

Relationship of Amakinite to other SpeciesHide

Member of:
Other Members of Brucite Group:
BruciteMg(OH)2Trig. 3m(32/m) : P3m1
PortlanditeCa(OH)2Trig. 3m(32/m) : P3m1
PyrochroiteMn(OH)2Trig. 3m(32/m) : P3m1
TheophrastiteNi(OH)2Trig. 3m(32/m) : P3m1

Common AssociatesHide

Associations Based on Photo Data:
1 photo of Amakinite associated with 'Limnite'

Related Minerals - Strunz-mindat GroupingHide

4.FE.NannoniiteAl2(OH)5FMon. 2/m : P21/b
4.FE.05BruciteMg(OH)2Trig. 3m(32/m) : P3m1
4.FE.05TheophrastiteNi(OH)2Trig. 3m(32/m) : P3m1
4.FE.05PortlanditeCa(OH)2Trig. 3m(32/m) : P3m1
4.FE.05PyrochroiteMn(OH)2Trig. 3m(32/m) : P3m1
4.FE.10DoyleiteAl(OH)3Tric. 1 : P1
4.FE.10BayeriteAl(OH)3Mon. 2/m : P21/m
4.FE.10NordstranditeAl(OH)3Tric. 1 : P1
4.FE.10GibbsiteAl(OH)3Mon. 2/m
4.FE.15LepidocrociteFe3+O(OH)Orth. mm2 : Cmc21
4.FE.15BöhmiteAlO(OH)Orth. mmm(2/m2/m2/m)
4.FE.20HeterogeniteCo3+O(OH)Hex.
4.FE.20GrimaldiiteCrO(OH)Trig. 3m : R3m
4.FE.25Lithiophorite(Al,Li)MnO2(OH)2Trig. 3m(32/m) : R3m
4.FE.25FeitknechtiteMn3+O(OH)Trig. 3m(32/m) : P3m1
4.FE.30QuenselitePbMnO2(OH)Mon. 2/m : P2/b
4.FE.35FerrihydriteFe3+10O14(OH)2Trig.
4.FE.40Vernadite(Mn4+,Fe3+,Ca,Na)(O,OH)2 · nH2OMon. 2/m : B2/m
4.FE.40FeroxyhyteFe3+O(OH)Hex.
4.FE.45QuetzalcoatliteZn6Cu3(TeO6)2(OH)6 · AgxPbyClx+2yTrig. 3m(32/m) : P31m
4.FE.50FuettereritePb3Cu2+6Te6+O6(OH)7Cl5 Trig. 3 : R3

Other InformationHide

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 AmakiniteHide

References for AmakiniteHide

Localities for AmakiniteHide

Showing 6 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.
Atlantic Ocean
 
  • Mid-Atlantic Ridge complex
    • Atlantis Massif
Beard et al. (2009)
France
 
  • Ile-de-France
    • Paris
Pignatelli (2016)
Germany
 
  • Bavaria
    • Lower Bavaria
      • Regen District
        • Bodenmais
Weiß (1990)
Greece
 
  • South Aegean
    • Thira
      • Santorini Island
        • Santorini Caldera
          • Palea Kameni Island
Puchelt et al. (1973)
Northwest Africa Meteorites
 
Jacquet et al. (2016)
Russia (TL)
 
  • Sakha
    • Mirninsky District
      • Daldyn
Kozlov et al. (1962) +1 other reference
 
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