Mineralogy Database

Middendorfite Mineral Data

Search Webmineral :

General Middendorfite Information

Help on Chemical  Formula: Chemical Formula: K3Na2Mn5Si12(O,OH)36•2H2O
Help on Composition: Composition: Molecular Weight = 1,408.07 gm
   Potassium   8.44 %  K    10.17 % K2O
   Sodium      3.38 %  Na    4.56 % Na2O
   Calcium     0.09 %  Ca    0.12 % CaO
   Magnesium   0.10 %  Mg    0.17 % MgO
   Titanium    0.10 %  Ti    0.17 % TiO2
   Manganese  19.31 %  Mn   24.94 % MnO
   Aluminum    0.11 %  Al    0.22 % Al2O3
   Zinc        0.14 %  Zn    0.17 % ZnO
   Iron        0.52 %  Fe    0.66 % FeO
   Silicon    23.82 %  Si   50.95 % SiO2
   Hydrogen    0.87 %  H     7.74 % H2O
   Oxygen     42.89 %  O
   Fluorine    0.23 %  F     0.23 % F
                -   %   F    -0.10 % -O=F2    
             ______        ______ 
             100.00 %      100.00 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: K3.04Na2.07Ca0.03Mn2+4.95Fe2+0.13Mg0.06Ti0.03Zn0.03Si11.94Al0.06O27.57(OH)8.26F0.17�1.92(H2O)
Help on Environment: Environment: Found in a hydrothermal assemblage in Hilairite hyperperalkaline pegmatite. Related to ganophyllite- and stilpnomelane-group minerals
Help on IMA Status: IMA Status: Approved IMA 2005 (Dana # Added)
Help on Locality: Locality: Kirovskii apatite mine, Kukisvumchorr, Khibiny alkaline massif, Kola Peninsula, Russia. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: Named for A.F. von Middendorff (1815-1894), an outstanding scientist, who carried out the first mineralogical investigations in the Khibiny pluton.
Help on Synonym: Synonym: IMA2005-028

Middendorfite Image

Click Here for Larger   Image in a New Browser Window Images:
Click Here for Larger   Image


Comments: Dark orange platy middendorfite in quartz matrix.
Location: Kirovskii Mine, Kukisvumchorr, Chibiny, Kola, Russia. Scale: Not Given.
© Diederik Visser

Middendorfite Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =2.1936:1:4.6949
Help on Cell Dimensions: Cell Dimensions: a = 12.55, b = 5.721, c = 26.86, Z = 2; beta = 114.04° V = 1,761.23 Den(Calc)= 2.65
Help on Crystal System: Crystal System: Monoclinic Space Group: P 21/m or P 21
Help on X Ray Diffraction: X Ray Diffraction: By Intensity(I/Io): 12.28(1), 2.84(0.9), 2.634(0.88),4.31(0.81), 2.366(0.76), 1.669(0.64), 3.555(0.62), 1.614(0.56),

Physical Properties of Middendorfite

Help on Cleavage: Cleavage: {001} Perfect
Help on Color: Color: Dark orange.
Help on Density: Density: 2.6
Help on Diaphaneity: Diaphaneity: Transparent
Help on Fracture: Fracture: Micaceous - Fracture of flexable micaceous cleavage fragments.
Help on Habit: Habit: Lamellar - Thin laminae producing a lamellar structure.
Help on Habit: Habit: Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)
Help on Habit: Habit: Tabular - Form dimensions are thin in one direction.
Help on Hardness: Hardness: 3-3.5 - Calcite-Copper Penny
Help on Luster: Luster: Vitreous (Glassy)
Help on Streak: Streak: pale yellow

Optical Properties of Middendorfite

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.003 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.022 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2087,KPDmeas= 0.2127,KC= 0.2133
Ncalc = 1.55 - 1.57
Help on Optical Data: Optical Data: Biaxial (-), a=1.534, b=1.562, g=1.563, bire=0.0290

Calculated Properties of Middendorfite

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=2.56 gm/cc
note: Specific Gravity of Middendorfite =2.60 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.01
Boson Index = 0.99
Help on Photoelectric: Photoelectric: PEMiddendorfite = 6.94 barns/electron
U=PEMiddendorfite x relectron= 17.78 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 120.09 (Gamma Ray American Petroleum Institute Units)
Concentration of Middendorfite per GRapi unit = 0.83 (%)

Estimated Radioactivity from Middendorfite - barely detectable


Middendorfite Classification

Help on  Dana Class: Dana Class: (74)Phyllosilicate Modulated Layers
  (74.01)with joined islands
  (74.01.01)Stilpnomelane group Stilpnomelane K(Fe,Mg,Fe)8(Si,Al)12(O,OH)27•n(H2O) P1 1 Lennilenapeite K6-7(Mg,Mn,Fe,Fe,Zn)48(Si,Al)72(O,OH)216•16(H2O) Unk (pseudo-HEX) Tri Franklinphilite (K,Na)4(Mn,Mg,Zn)48(Si,Al)72(O,OH)216•6(H2O) pseudo-HEX P1 or P1 Tri Bannisterite KCa(Mn,Fe,Zn,Mg)21(Si,Al)32O76(OH)16•4-12(H2O) A2/a 2/m Middendorfite! K3Na2Mn5Si12(O,OH)36•2H2O P 21/m or P 21 Mono
Help on  Strunz Class: Strunz Class: 09.EJ.10 09 - SILICATES (Germanates)
  09.E - Phyllosilicates
  09.EJ -Unclassified phyllosilicates
09.EJ.10 Middendorfite! K3Na2Mn5Si12(O,OH)36•2H2O P 21/m or P 21 Mono

Other Middendorfite Information

Help on References: References: NAME( Geology of Ore Deposits, v49:522) PHYS. PROP.(Geology of Ore Deposits, v49:522) OPTIC PROP.(Geology of Ore Deposits, v49:522)
Help on See Also: See Also: Links to other databases for Middendorfite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - MinDAT
7 - Mineralienatlas (Deutsch)
8 - Online Mineral Museum
9 - QUT Mineral Atlas
10 - Ruff.Info

Search for Middendorfite using:

Web webmineral.com
[AOL] [Bing] [Dog Pile] [GeoScienceWorld] [HotBot] [Ixquick] [Lycos] [MAMMA] [Scirus] [Teoma] [WebCrawler] [Wikipedia] [YAHOO]

Visit our Advertisers for Middendorfite :

Ask about Middendorfite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

Print or Cut-and-Paste your Middendorfite Specimen Label here :


Dana No: Strunz No: 09.EJ.10





Dakota Matrix
Excalibur Minerals
Exceptional Minerals
Hudson Insitute
John Betts Fine Minerals
Mc Dougall Minerals
Mineral News
Rock and Mineral Shows
Weinrich Minerals, Inc.