Rittmannite Mineral Data

General Rittmannite Information

Chemical Formula:

Mn++Mn++Fe++Al2(OH)2(PO4)4•8(H2O)

Composition:

Molecular Weight = 777.71 gm

Manganese 14.13 % Mn 18.24 % MnO

Aluminum 6.94 % Al 13.11 % Al₂O₃

Iron 7.18 % Fe 9.24 % FeO

Phosphorus 15.93 % P 36.50 % P₂O₅

Hydrogen 2.33 % H 20.85 % H₂O

Oxygen 53.49 % O

______ ______

100.00 % 97.94 % = TOTAL OXIDE

Empirical Formula:

Mn²⁺₂Fe²⁺Al₂(OH)₂(PO₄)₄•8(H₂O)

Environment:

Rare mineral in phosphatic nodules in zoned granite pegmatite veins.

IMA Status:

Approved IMA 1989

Locality:

Mangualde pegmatite, near Mesquitela, and the Bendada pegmatite, near Guarda, Portugal. Link to MinDat.org Location Data.

Name Origin:

Named for Alfred Rittmann (1893-1980), German petrologist and volcanologist, University of Catania, Catania, Italy.

Name Pronunciation:

Rittmannite + Pronunciation

Rittmannite Image

Images:

Rittmannite

Comments: SEM image of rittmannite crystals on massive adularia. (CanMin, v27:447).
Location: Found in altered phosphatic "nodules" from the Mangualde granitic pegmatite, Portugal. Scale: 240 X.
© Canadian Mineralogist

Images:

Rittmannite

Comments: Light yellow, opaque, microcrystalline rittmannite on matrix.
Location: El Galineiro, Vigo, Pontevedra, Spain. Scale: Specimen Size 2.4 x 2.1 x 1.1 cm.
© John Veevaert

Rittmannite Crystallography

Axial Ratios:

a:b:c =2.1785:1:1.4746

Cell Dimensions:

a = 15.01, b = 6.89, c = 10.16, Z = 2; beta = 112.82° V = 968.49 Den(Calc)= 2.67

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 2/a

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 9.38(1), 2.802(0.8), 4.69(0.5),

Physical Properties of Rittmannite

Cleavage:

{???} Indistinct

Color:

Light yellow.

Density:

2.81

Diaphaneity:

Transparent

Hardness:

3.5 - Copper Penny

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Rittmannite

Gladstone-Dale:

CI meas= -0.035 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.09 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2377,KPDmeas= 0.2259,KC= 0.2181
Ncalc = 1.58 - 1.61

Optical Data:

Biaxial (+), a=1.622, b=1.628, g=1.654, bire=0.0320, 2V(Calc)=52, 2V(Meas)=43.

Calculated Properties of Rittmannite

Electron Density:

Bulk Density (Electron Density)=2.80 gm/cc
note: Specific Gravity of Rittmannite =2.81 gm/cc.

Fermion Index:

Fermion Index = 0.0017826091
Boson Index = 0.9982173909

Photoelectric:

PE_Rittmannite= 6.63 barns/electron
U=PE_Rittmannite x rElectron Density= 18.58 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Rittmannite is Not Radioactive

Rittmannite Classification

Dana Class:

42.11.03.04 (42)Hydrated Phosphates, etc., Containing Hydroxyl or Halogen

(42.11)where (AB)4 (XO4)3 Zq ï¿½ x(H2O)

(42.11.03)Whiteite Group

42.11.03.01 Whiteite-(CaFeMg) Ca(Fe,Mn)Mg2Al2(PO4)4(OH)2•8(H2O) P 2₁/a 2/m

42.11.03.02 Whiteite-(MnFeMg) (Mn,Ca)(Fe,Mn)Mg2Al2(PO4)4(OH)2•8(H2O) P 2/a 2/m

42.11.03.03 Whiteite-(CaMnMg) CaMnMg2Al2(PO4)4(OH)2•8(H2O) P 2/a 2/m

42.11.03.04 Rittmannite MnMnFeAl2(OH)2(PO4)4•8(H2O) P 2/a 2/m

42.11.03.05 Jahnsite-(CaFeFe)! (Ca,Mn)(Fe,Mn)Fe2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m

42.11.03.06 Jahnsite-(NaFeMg)! NaFeMg2Fe2(PO4)4(OH)2•8H2O P 2/a 2/m

42.11.03.07 Jahnsite-(CaMgMg)! CaMgMg2Fe2(PO4)4(OH)2•8H2O P 2/a 2/m

42.11.03.08 Jahnsite-(NaMnMg)! NaMnMg2Fe2(PO4)4(OH)2•8H2O P 2/a 2/m

Strunz Class:

08.DH.15 08 - PHOSPHATES, ARSENATES, VANADATES

08.D - Phosphates, etc

08.DH -With large and medium-sized cations, (OH, etc.):RO4 < 1:1

08.DH.15 Keckite Ca(Mn,Zn)2Fe3(PO4)4(OH)3•2(H2O) P 2₁/a 2/m

08.DH.15 Jahnsite-(CaMnFe) CaMnFe2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m

08.DH.15 Jahnsite-(CaMnMg) CaMnMg2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m

08.DH.15 Jahnsite-(CaMnMn) CaMnMn2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m

08.DH.15 Jahnsite-(MnMnMn)* MnMnMn2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m

08.DH.15 Kaluginite* (Mn,Ca)MgFe(PO4)2(OH)•4(H2O) C cca 2/m 2/m 2/m

08.DH.15 Rittmannite MnMnFeAl2(OH)2(PO4)4•8(H2O) P 2/a 2/m

08.DH.15 Whiteite-(MnFeMg) (Mn,Ca)(Fe,Mn)Mg2Al2(PO4)4(OH)2•8(H2O) P 2/a 2/m

08.DH.15 Whiteite-(CaFeMg) Ca(Fe,Mn)Mg2Al2(PO4)4(OH)2•8(H2O) P 2₁/a 2/m

08.DH.15 Whiteite-(CaMnMg) CaMnMg2Al2(PO4)4(OH)2•8(H2O) P 2/a 2/m

08.DH.15 Jahnsite-(CaFeFe)! (Ca,Mn)(Fe,Mn)Fe2Fe2(PO4)4(OH)2•8(H2O) P 2/a 2/m

08.DH.15 Jahnsite-(NaFeMg)! NaFeMg2Fe2(PO4)4(OH)2•8H2O P 2/a 2/m

08.DH.15 Jahnsite-(CaMgMg)! CaMgMg2Fe2(PO4)4(OH)2•8H2O P 2/a 2/m

08.DH.15 Jahnsite-(NaMnMg)! NaMnMg2Fe2(PO4)4(OH)2•8H2O P 2/a 2/m

Other Rittmannite Information

References:

NAME( AntBidBlaNic4) PHYS. PROP.(Am.Min.,Vol.75,p932,1990) OPTIC PROP.(Am.Min.,Vol.75,p932,1990)

See Also:

Links to other databases for Rittmannite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info

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

Rittmannite

Mn++Mn++Fe++Al2(OH)2(PO4)4•8(H2O)
Dana No: 42.11.03.04 Strunz No: 08.DH.15
Locality:

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