Gjerdingenite-Ca Mineral Data

General Gjerdingenite-Ca Information

Chemical Formula:

K2Ca(Nb,Ti)4(Si4O12)2(O,OH)4•6H2O

Composition:

Molecular Weight = 1,216.40 gm

Potassium 2.99 % K 3.60 % K₂O

Barium 0.90 % Ba 1.01 % BaO

Sodium 0.85 % Na 1.15 % Na₂O

Strontium 2.95 % Sr 3.49 % SrO

Calcium 2.54 % Ca 3.55 % CaO

Titanium 5.98 % Ti 9.98 % TiO₂

Manganese 0.63 % Mn 0.82 % MnO

Niobium 19.17 % Nb 27.42 % Nb₂O₅

Aluminum 0.07 % Al 0.13 % Al₂O₃

Zinc 0.05 % Zn 0.07 % ZnO

Iron 0.14 % Fe 0.18 % FeO

Silicon 18.40 % Si 39.37 % SiO₂

Hydrogen 1.03 % H 9.24 % H₂O

Oxygen 44.29 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

K_0.93Na_0.45Sr_0.41Ca_0.15Ba_0.08Ca_0.62Mn²⁺_0.14Fe²⁺_0.03Zn_0.01Nb_2.51Ti_1.52Si_7.97Al_0.03 O₂₄O_2.86(OH)_1.14ï¿½5.67(H₂O)

Environment:

Found in peralkaline pegmatites related to agpaitic feldspathoidal syenites as an alteration product of vuonnemite. Labuntsovite group

IMA Status:

Approved IMA 2005 (Dana # Added)

Locality:

Pegmatite #61, Karnasurt, Lovozero, Kola Peninsula, Russia Link to MinDat.org Location Data.

Name Origin:

Named as the Ca-dominant analogue of gjerdingenite-Fe

Synonym:

IMA2005-029

Gjerdingenite-Ca Image

Images:

Gjerdingenite-Ca

Comments: Tiny brown fragment of gjerdingenite-Ca.
Location: Pegmatite No. 61, Karnasurt Mt, Lovozero Massif, Kola Peninsula, Russia. Scale: Not Given.
© Sergey Vasiliev / Systematic Mineralogy

Gjerdingenite-Ca Crystallography

Axial Ratios:

a:b:c =1.0303:1:0.5555

Cell Dimensions:

a = 14.6365, b = 14.2049, c = 7.8919, Z = 2; beta = 117.467° V = 1,455.85 Den(Calc)= 2.77

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): 7.1(1), 6.999(0.88), 4.985(0.78),3.167(0.46), 3.252(0.42), 6.476(0.38), 3.14(0.36),

Physical Properties of Gjerdingenite-Ca

Cleavage:

None

Color:

White, Pale brown, Pinkish brown.

Density:

2.79

Diaphaneity:

Transparent to Opaque

Fracture:

Brittle - Uneven - Very brittle fracture producing uneven fragments.

Habit:

Pseudomorphous - Occurs in the form of another mineral.

Hardness:

5 - Apatite

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Gjerdingenite-Ca

Gladstone-Dale:

CI meas= -0.009 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.017 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2556,KPDmeas= 0.2538,KC= 0.2514
Ncalc = 1.7

Optical Data:

Biaxial (+), a=1.68, b=1.682, g=1.762, bire=0.0820, 2V(Calc)=20, 2V(Meas)=25. Dispersion dispersion not observed.

Calculated Properties of Gjerdingenite-Ca

Electron Density:

Bulk Density (Electron Density)=2.72 gm/cc
note: Specific Gravity of Gjerdingenite-Ca =2.79 gm/cc.

Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Photoelectric:

PE_{Gjerdingenite-Ca}= 37.32 barns/electron
U=PE_{Gjerdingenite-Ca} x r_electron= 101.49 barns/cc.

Radioactivity:

GRapi = 42.05 (Gamma Ray American Petroleum Institute Units)
Concentration of Gjerdingenite-Ca per GRapi unit = 2.38 (%)

Estimated Radioactivity from Gjerdingenite-Ca - barely detectable

Gjerdingenite-Ca Classification

Dana Class:

60.01.03e.07 (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-Ca Information

References:

NAME( AmMin, v92:1776) PHYS. PROP.(AmMin, v92:1776) OPTIC PROP.(AmMin, v92:1776)

See Also:

Links to other databases for Gjerdingenite-Ca :
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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Gjerdingenite-Ca

K2Ca(Nb,Ti)4(Si4O12)2(O,OH)4•6H2O
Dana No: 60.01.03e.07 Strunz No: 09.CE.30c
Locality:

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