Gjerdingenite-Fe Mineral Data

General Gjerdingenite-Fe Information

Chemical Formula:

K2[(H2O)2(Fe,Mn)][(Nb,Ti)4(Si4O12)2(O,OH)4]•4(H2O)

Composition:

Molecular Weight = 1,242.18 gm

Potassium 6.30 % K 7.58 % K₂O

Titanium 3.85 % Ti 6.43 % TiO₂

Manganese 1.11 % Mn 1.59 % Mn₂O₃

Niobium 22.44 % Nb 32.10 % Nb₂O₅

Iron 3.37 % Fe 4.82 % Fe₂O₃

Silicon 18.09 % Si 38.70 % SiO₂

Hydrogen 1.05 % H 9.43 % H₂O

Oxygen 43.79 % O

______ ______

100.00 % 100.64 % = TOTAL OXIDE

Empirical Formula:

K₂(H₂O)₂Fe³⁺_0.75Mn³⁺_0.25Nb₃Ti(Si₄O₁₂)₂O₃(OH)�4(H₂O)

Environment:

Found in miarolitic cavities in ekerite, a sodic granite. (labuntosovite group; structure)

IMA Status:

Approved IMA 2002 (Dana # Added)

Locality:

Gjerdingselva, Lunnar, Pooland, Norway. Link to MinDat.org Location Data.

Name Origin:

Named after the locality.

Synonym:

IMA2001-009

Gjerdingenite-Fe Image

Images:

Gjerdingenite-Fe

Comments: Brown crystals of gjerdingenite-Fe on matrix.
Location: Gjerdingen, Vestbygda, Nordmarka, Jevnaker, Oppland, Norway. Scale: Picture size 1.2 mm.
© Thomas Witzke / Abraxas-Verlag

Images:

Gjerdingenite-Fe Ralstonite

Comments: SEM photomicrograph of gjerdingenite-Fe. The mineral is dusted with tiny crystals of two phases. At high magnification, one of them is seen to form cubes and is probably ralstonite.
Location: Gjerdingselva, Lunner, Oppland, Oslo Region, Norway. Scale: Crystal length 0.5 mm.
© Canadian Mineralogist

Gjerdingenite-Fe Crystallography

Axial Ratios:

a:b:c =1.042:1:0.562

Cell Dimensions:

a = 14.529, b = 13.943, c = 7.837, Z = 2; beta = 117.61° V = 1,406.81 Den(Calc)= 2.93

Crystal System:

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

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

By Intensity(I/I_o): 3.225(1)(421,400,402), 6.92(0.8)(020,001), 4.94(0.7)(021), 3.114(0.67)(041,022), 2.512(0.5)(441,401,403)6.42(0.5)(200,201),

Physical Properties of Gjerdingenite-Fe

Cleavage:

None

Color:

Pale yellow, Yellow, Yellow orange.

Density:

2.82

Diaphaneity:

Translucent to transparent

Fracture:

Brittle - Uneven - Very brittle fracture producing uneven fragments.

Habit:

Aggregates - Made of numerous individual crystals or clusters.

Habit:

Lath - Shaped like a small, thin plaster lath, tabular (rectangular) in shape.

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Hardness:

5 - Apatite

Luster:

Vitreous - Waxy

Streak:

faint yellowish white

Optical Properties of Gjerdingenite-Fe

Gladstone-Dale:

CI meas= 0.012 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.049 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2459,KPDmeas= 0.2555,KC= 0.2587
Ncalc = 1.73 - 1.76

Optical Data:

Biaxial (+), a=1.6676, b=1.7001, g=1.794, bire=0.1264, 2V(Calc)=64, 2V(Meas)=58.5. Dispersion dispersion not observed.

Calculated Properties of Gjerdingenite-Fe

Electron Density:

Bulk Density (Electron Density)=2.75 gm/cc
note: Specific Gravity of Gjerdingenite-Fe =2.82 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_{Gjerdingenite-Fe}= 35.82 barns/electron
U=PE_{Gjerdingenite-Fe} x r_electron= 98.51 barns/cc.

Radioactivity:

GRapi = 88.57 (Gamma Ray American Petroleum Institute Units)
Concentration of Gjerdingenite-Fe per GRapi unit = 1.13 (%)

Estimated Radioactivity from Gjerdingenite-Fe - barely detectable

Gjerdingenite-Fe Classification

Dana Class:

60.01.03e.06 (60)Cyclosilicate Four-Membered Rings

(60.01)as Titanosilicates

(60.01.03e)Labuntsovite Group (Labuntsovite subgroup Monoclinic [C2/m])

60.01.03e.01 Labuntsovite-Mn! Na4K4(Ba,K)(Mn,Fe)1x(Ti,Nb)8[Si4O12]4(O,OH)8•n(H2O),n=10-12 I2/m 2/m

60.01.03e.02 Labuntsovite-Mg! Na4K4(Ba,K)(Mg,Fe)1xTi8(Si4O12)4(O,OH)8•10(H2O) C 2/m 2/m

60.01.03e.03 Labuntsovite-Fe! Na4K4(Ba,K)2(Fe,Mg,Mn)1xTi8(Si4O12)4(O,OH)8•10(H2O) C 2/m 2/m

60.01.03e.04 Paratsepinite-Na! (Na,Sr,K,Ca)7(Ti,Nb)8[Si4O12]4(O,OH)8•n(H2O)n~8 C 2/m 2/m

60.01.03e.05 Gjerdingenite-Mn! (K,Na)2(Mn,Fe)(Nb,Ti)4(Si4O12)2(O,OH)4•6(H2O) C 2/m 2/m

60.01.03e.06 Gjerdingenite-Fe! K2[(H2O)2(Fe,Mn)][(Nb,Ti)4(Si4O12)2(O,OH)4]•4(H2O) C 2/m 2/m

60.01.03e.07 Gjerdingenite-Ca! K2Ca(Nb,Ti)4(Si4O12)2(O,OH)4•6H2O C 2/m 2/m

60.01.03e.08 Gjerdingenite-Na! (K,Na)2Na(Nb,Ti)4(Si4O12)2(OH,O)4•5H2O C 2/m 2/m

Strunz Class:

09.CE.30c 09 - SILICATES (Germanates)

09.C - Cyclosilicates

09.CE -[Si4O12]8- 4-membered single rings (vierer-Einfachringe),

09.CE.30c Gjerdingenite-Mn! (K,Na)2(Mn,Fe)(Nb,Ti)4(Si4O12)2(O,OH)4•6(H2O) C 2/m 2/m

09.CE.30c Karupmollerite-Ca! (Na,Ca,K)2Ca(Nb,Ti)4(Si4O12)2(O,OH)4•7(H2O) C 2/m 2/m

09.CE.30c Kuzmenkoite-Zn! K2Zn(Ti,Nb)4(Si4O12)2(OH,O)4•6-8(H2O) Cm m

09.CE.30c Kuzmenkoite-Mn! (K,Na)2(Mn,Fe)(Ti,Nb)4[Si4O12]2(OH)4•5(H2O) C 2/m 2/m

09.CE.30c Gjerdingenite-Fe! K2[(H2O)2(Fe,Mn)][(Nb,Ti)4(Si4O12)2(O,OH)4]•4(H2O) C 2/m 2/m

09.CE.30c Lepkhenelmite-Zn! Ba2Zn(Ti,Nb)4(Si4O12)2(O,OH)4•7(H2O) Cm m

09.CE.30c Gjerdingenite-Ca! K2Ca(Nb,Ti)4(Si4O12)2(O,OH)4•6H2O C 2/m 2/m

09.CE.30c Gjerdingenite-Na! (K,Na)2Na(Nb,Ti)4(Si4O12)2(OH,O)4•5H2O C 2/m 2/m

09.CE.30c Burovaite-Ca! (K,Na)4Ca2(Ti,Nb)8[Si4O12]4(OH,O)8•12H2O C 2/m 2/m

Other Gjerdingenite-Fe Information

References:

NAME( CanMin, v 41, p 810) PHYS. PROP.(CanMin, v 41, p 810) OPTIC PROP.(CanMin, v 41, p 810)

See Also:

Links to other databases for Gjerdingenite-Fe :
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

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Print or Cut-and-Paste your Gjerdingenite-Fe Specimen Label here :

Gjerdingenite-Fe

K2[(H2O)2(Fe,Mn)][(Nb,Ti)4(Si4O12)2(O,OH)4]•4(H2O)
Dana No: 60.01.03e.06 Strunz No: 09.CE.30c
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