Middendorfite
A valid IMA mineral species
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About Middendorfite
Formula:
K3Na2Mn5Si12(O,OH)36 · 2H2O
Colour:
Dark to bright orange
Lustre:
Vitreous
Hardness:
3 - 3½
Specific Gravity:
2.60
Crystal System:
Monoclinic
Name:
For Aleksandr Fedorovich von Middendorf (18 August 1815 – 24 January 1894), a German-Russian scientist who made the first mineralogical studies on the Khibiny massif.
Unique Identifiers
Mindat ID:
28996
Long-form identifier:
mindat:1:1:28996:8
GUID
(UUID V4):
(UUID V4):
358c864f-3b30-4dc8-b7a4-b8f712727828
Classification of Middendorfite
Approved
Approval year:
2005
First published:
2006
Type description reference:
9.EJ.10
9 : SILICATES (Germanates)
E : Phyllosilicates
J : Unclassified phyllosilicates
9 : SILICATES (Germanates)
E : Phyllosilicates
J : Unclassified phyllosilicates
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
Symbol | Source | Reference |
---|---|---|
Mdd | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Middendorfite
Vitreous
Transparency:
Transparent
Colour:
Dark to bright orange
Streak:
yellowish
Hardness:
3 - 3½ on Mohs scale
Tenacity:
Flexible
Cleavage:
Perfect
on (001)
on (001)
Fracture:
Sub-Conchoidal
Comment:
fracture scaly
Density:
2.60 g/cm3 (Measured) 2.65 g/cm3 (Calculated)
Optical Data of Middendorfite
Type:
Biaxial (-)
RI values:
nα = 1.534(3) nβ = 1.562(2) nγ = 1.563(2)
2V:
Measured: 10° (5), Calculated: 21°
Max Birefringence:
δ = 0.029
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
and does not take into account mineral colouration.
Surface Relief:
Low
Pleochroism:
Strong
Comments:
X = yellowish to colorless; Y = brown;
Z = deep brown
Z = deep brown
Chemical Properties of Middendorfite
Formula:
K3Na2Mn5Si12(O,OH)36 · 2H2O
Crystallography of Middendorfite
Crystal System:
Monoclinic
Cell Parameters:
a = 12.55(1) Å, b = 5.721(2) Å, c = 26.86(2) Å
β = 114.04(7)°
β = 114.04(7)°
Ratio:
a:b:c = 2.194 : 1 : 4.695
Unit Cell V:
1761 ų
Z:
2
Comment:
Point Group: 2/m or 2; Space Group: P21/m or P21.
X-Ray Powder Diffraction
Powder Diffraction Data:
d-spacing | Intensity |
---|---|
12.28 Å | (100) |
2.840 Å | (90) |
2.634 Å | (88) |
4.31 Å | (81) |
2.366 Å | (76) |
1.669 Å | (64) |
3.555 Å | (62) |
Geological Environment
Paragenetic Mode(s):
Paragenetic Mode | Earliest Age (Ga) |
---|---|
Stage 4b: Highly evolved igneous rocks | >3.0 |
35 : Ultra-alkali and agpaitic igneous rocks |
Type Occurrence of Middendorfite
General Appearance of Type Material:
Coarse, rhomb-like lamellar and tabular crystals up to 0.1 x 0.2 x 0.4 mm in size, combined in worm- and fan-like aggregates up to 1 mm
Place of Conservation of Type Material:
A.E. Fersman Mineralogical Museum, Russian Academy of Sciences, Moscow, 3312/1.
Geological Setting of Type Material:
late hydrothermal mineral in a hyperperalkaline pegmatite
Associated Minerals at Type Locality:
Reference:
Pekov, I.V., Chukanov, N.V., Dubinchuk, V.T., Zadov, A.E. (2006) Middendorfite, K3Na2Mn5Si12(O,OH)36• 2H2O, a new mineral from Khibiny Massif, Kola Peninsula. Proceedings of the Russian Mineralogical Society: 135(3): 42–52.
Synonyms of Middendorfite
Related Minerals - Strunz-mindat Grouping
9.EJ.05 | Lourenswalsite | (K,Ba)2(Ti,Mg,Ca,Fe)4(Si,Al,Fe)6O14(OH)12 | Hex. |
9.EJ.15 | Lipuite | KNa8Mn3+5 Mg0.5[Si12O30(OH)4](PO4)O2(OH)2 · 4H2O | Orth. mmm (2/m 2/m 2/m) : Pnnm |
9.EJ.20 | Odigitriaite | CsNa5Ca5[Si14B2O38]F2 | Mon. 2/m : B2/b |
Other Information
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 Middendorfite
mindat.org URL:
https://www.mindat.org/min-28996.html
Please feel free to link to this page.
Please feel free to link to this page.
External Links:
Mineral Dealers:
References for Middendorfite
Reference List:
Localities for Middendorfite
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).
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.
All localities listed without proper references should be considered as questionable.
Russia (TL) | |
|
Hilairitovoye pegmatite, Kirovskii apatite mine, Kukisvumchorr Mt, Khibiny Massif, Murmansk Oblast, Russia