Gmelinite-K Mineral Data

General Gmelinite-K Information

Chemical Formula:

(K,Na,Ca)6(Al7Si17O48)•22(H2O)

Composition:

Molecular Weight = 2,032.96 gm

Potassium 6.25 % K 7.53 % K₂O

Sodium 1.96 % Na 2.64 % Na₂O

Calcium 1.12 % Ca 1.57 % CaO

Aluminum 9.81 % Al 18.53 % Al₂O₃

Silicon 23.62 % Si 50.54 % SiO₂

Hydrogen 2.15 % H 19.19 % H₂O

Oxygen 55.09 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

K_3.25Ca_0.57Na_1.73Al_7.39Si_17.1O_48.34•21.66(H₂O)

Environment:

Druzy cavities within brecciated pegmatite in alkaline rocks.

IMA Status:

Approved IMA 2001 (Dana # Added)

Locality:

Lovozero alkaline massif, Kola Peninsula, Russia. Link to MinDat.org Location Data.

Name Origin:

Named after the German mineralogist and chemist, Christian Gottlob Gmelin (1792-1860) of Turbingen, Germany. The K-dominant member of the gmelinite series.

Name Pronunciation:

Gmelinite-K + Pronunciation

Synonym:

IMA1999-039

Gmelinite-K Image

Images:

Gmelinite-K

Comments: Pink to reddish brown gmelinite-K crystals in a cavity in matrix.
Location: Fara Vicentino, Vicenza, Veneto, Italy. Scale: Not Given.
© Diederik Visser

Gmelinite-K Crystallography

Axial Ratios:

a:c = 1:0.7528

Cell Dimensions:

a = 13.621, c = 10.254, Z = 1; V = 1,647.56 Den(Calc)= 2.05

Crystal System:

Hexagonal - Dihexagonal Dipyramidal H-M Symbol (6/m 2/m 2/m) Space Group: P 6₃/mmc

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

By Intensity(I/I_o): 2.719(1)(123), 4.11(1)(121,112), 1.817(0.8),2.852(0.8)(041,222), 2.971(0.8)(040), 11.9(0.8)(010), 5.16(0.7)(021,002), 3.27(0.7)(130,013), 2.085(0.5),

Physical Properties of Gmelinite-K

Cleavage:

{1010} Good, {0001} Parting

Color:

Colorless, Brownish white.

Density:

Diaphaneity:

Transparent

Fracture:

Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.

Habit:

Aggregates - Made of numerous individual crystals or clusters.

Habit:

Granular - Generally occurs as anhedral to subhedral crystals in matrix.

Habit:

Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)

Hardness:

4 - Fluorite

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Gmelinite-K

Gladstone-Dale:

CI meas= -0.022 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.003 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2312,KPDmeas= 0.237,KC= 0.2318
Ncalc = 1.46 - 1.48

Optical Data:

Uniaxial (-), e=1.471, w=1.477, bire=0.0060.

Calculated Properties of Gmelinite-K

Electron Density:

Bulk Density (Electron Density)=2.08 gm/cc
note: Specific Gravity of Gmelinite-K =2.05 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Gmelinite-K= 2.02 barns/electron
U=PE_Gmelinite-K x r_electron= 4.19 barns/cc.

Radioactivity:

GRapi = 91.48 (Gamma Ray American Petroleum Institute Units)
Concentration of Gmelinite-K per GRapi unit = 1.09 (%)

Estimated Radioactivity from Gmelinite-K - barely detectable

Gmelinite-K Classification

Dana Class:

77.01.02.06b (77)Tectosilicate Zeolite group

(77.01)true zeolites

(77.01.02)Chabazite and related species

77.01.02.01 Chabazite-Ca (Ca0.5,Na,K)4[Al4Si8O24]•12H2O P1 1

77.01.02.01a Chabazite-Na! (Na2,K2,Ca,Mg)[Al2Si4O12]•6(H2O) R 3m 3 2/m

77.01.02.01b Chabazite-K! (K2,Ca,Na2,Mg)[Al2Si4O12]•6(H2O) R 3m 3 2/m

77.01.02.01c Chabazite-Sr! (Sr,Ca,K2,Na2)[Al2Si4O12]•6(H2O) R 3m 3 2/m

77.01.02.02 Herschelite? (Na,Ca,K)AlSi2O6•3(H2O) R 3m 3 2/m

77.01.02.03 Willhendersonite KCaAl3Si3O12•5(H2O) P1 1

77.01.02.04 Offretite (K2,Ca,Mg)2.5Al5Si13O36•15(H2O) P 6m2 6 m2

77.01.02.05 Erionite-Na (Na2,K2,Ca)2[Al4Si14O36]•15(H2O) P 6₃/mmc 6/m 2/m 2/m

77.01.02.05a Erionite-K! (K2,Ca,Na2)2[Al4Si14O36]•15(H2O) P 6₃/mmc 6/m 2/m 2/m

77.01.02.05b Erionite-Ca! (Ca,K2,Na2)2[Al4Si14O36]•15(H2O) P 6₃/mmc 6/m 2/m 2/m

77.01.02.06 Gmelinite-Na (Na2,Ca)Al2Si4O12•6(H2O) P 6₃/mmc 6/m 2/m 2/m

77.01.02.06a Gmelinite-Ca! (Ca,Na2)Al2Si4O12•6(H2O) P 6₃/mmc 6/m 2/m 2/m

77.01.02.06b Gmelinite-K! (K,Na,Ca)6(Al7Si17O48)•22(H2O) P 6₃/mmc 6/m 2/m 2/m

77.01.02.07 Faujasite-Na (Na2,Ca,Mg)3.5[Al7Si17O48]•32(H2O) F d3m 4/m 3 2/m

77.01.02.07a Faujasite-Ca! (Ca,Na2,Mg)3.5[Al7Si17O48]•32(H2O) F d3m 4/m 3 2/m

77.01.02.07b Faujasite-Mg! (Mg,Na2,Ca)3.5[Al7Si17O48]•32(H2O) F d3m 4/m 3 2/m

77.01.02.08 Levyne-Ca (Ca,Na2,K2)Al2Si4O12•6(H2O) R 3m 3 2/m

77.01.02.08a Levyne-Na! (Na2,Ca,K2)Al2Si4O12•6(H2O) R 3m 3 2/m

77.01.02.09 Tschortnerite! Ca4(Ca,Sr,K,Ba)3Cu3(OH)8[Si12Al12O48]•x(H2O),x>=20 F m3m 4/m 3 2/m

Strunz Class:

09.GD.05 09 - SILICATES (Germanates)

09.G - Tektosilicates with Zeolitic H2O

09.GD -Chains of 6-membered rings ï¿½ tabular zeolites

09.GD.05 Gmelinite-Ca! (Ca,Na2)Al2Si4O12•6(H2O) P 6₃/mmc 6/m 2/m 2/m

09.GD.05 Gmelinite-K! (K,Na,Ca)6(Al7Si17O48)•22(H2O) P 6₃/mmc 6/m 2/m 2/m

09.GD.05 Gmelinite-Na (Na2,Ca)Al2Si4O12•6(H2O) P 6₃/mmc 6/m 2/m 2/m

Other Gmelinite-K Information

References:

NAME( AmMin, 87:1510) PHYS. PROP.(AmMin, 87:1510, CanMin, v 35, p 1583) OPTIC PROP.(AmMin, 87:1510)

See Also:

Links to other databases for Gmelinite-K :
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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Gmelinite-K

(K,Na,Ca)6(Al7Si17O48)•22(H2O)
Dana No: 77.01.02.06b Strunz No: 09.GD.05
Locality:

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