Perlialite Mineral Data

General Perlialite Information

Chemical Formula:

K8Tl4Al12Si24O72•20(H2O)

Composition:

Molecular Weight = 3,027.26 gm

Potassium 10.33 % K 12.45 % K₂O

Aluminum 10.70 % Al 20.21 % Al₂O₃

Thallium 6.75 % Tl 7.54 % Tl₂O₃

Silicon 22.27 % Si 47.63 % SiO₂

Hydrogen 1.33 % H 11.90 % H₂O

Oxygen 48.62 % O

______ ______

100.00 % 99.74 % = TOTAL OXIDE

Empirical Formula:

K₈TlAl₁₂Si₂₄O₇₂•20(H₂O)

IMA Status:

Approved IMA 1984

Locality:

Pegmatites of Mt.Eveslogchorr and Mt. Yukspor, Khibina alkaline massif, Kola Peninsula, Russia. Link to MinDat.org Location Data.

Name Origin:

Named after Lily Alekseevna Perekrest, teacher of mineralogy at the Kirovsk Mining Technical School

Name Pronunciation:

Perlialite + Pronunciation

Synonym:

ICSD 69404

PDF 38-395

Perlialite Image

Images:

Perlialite

Comments: Opaque white fibrous perlialite coating on syenite rock.
Location: Khibiny Massif, Kola Peninsula, Murmansk District, Russia. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Perlialite Crystallography

Axial Ratios:

a:c = 1:0.40616

Cell Dimensions:

a = 18.49, c = 7.51, Z = 1; V = 2,223.54 Den(Calc)= 2.26

Crystal System:

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

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

By Intensity(I/I_o): 1.306(1), 4.62(1), 16(1),

Physical Properties of Perlialite

Color:

Pearl white.

Density:

2.14

Hardness:

4-5 - Fluorite-Apatite

Luster:

Pearly

Streak:

white

Optical Properties of Perlialite

Gladstone-Dale:

CI meas= -0.082 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.024 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2148,KPDmeas= 0.2269,KC= 0.2098
Ncalc = 1.45 - 1.47

Optical Data:

Biaxial (?), a=1.483, g=1.488, bire=0.0050

Calculated Properties of Perlialite

Electron Density:

Bulk Density (Electron Density)=2.24 gm/cc
note: Specific Gravity of Perlialite =2.26 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Perlialite= 102.38 barns/electron
U=PE_Perlialite x r_electron= 229.46 barns/cc.

Radioactivity:

GRapi = 147.85 (Gamma Ray American Petroleum Institute Units)
Concentration of Perlialite per GRapi unit = 0.68 (%)

Estimated Radioactivity from Perlialite - barely detectable

Perlialite Classification

Dana Class:

77.01.03.08 (77)Tectosilicate Zeolite group

(77.01)true zeolites

(77.01.03)Gismondine and related species

77.01.03.01 Gismondine Ca2Al4Si4O16•9(H2O) P 2₁/c 2/m

77.01.03.02 Amicite K2Na2Al4Si4O16•5(H2O) I2 2

77.01.03.03 Garronite Na2Ca5Al12Si20O64•27(H2O) I 4₁/a 4/m

77.01.03.04 Gobbinsite (Na2,Ca)2K2Al6Si10O32•12(H2O) P mn2₁ mm2

77.01.03.05 Harmotome (Ba,Na,K)1-2(Si,Al)8O16•6(H2O) P 2₁/m 2/m

77.01.03.06 Phillipsite-Na (Na,K,Ca)1-2(Si,Al)8O16•6(H2O) P 2₁/m 2/m

77.01.03.06a Phillipsite-Ca! (Ca,K,Na)1-2(Si,Al)8O16•6(H2O) P 2₁/m 2/m

77.01.03.06b Phillipsite-K! (K,Na,Ca)1-2(Si,Al)8O16•6(H2O) P 2₁/m 2/m

77.01.03.08 Perlialite K8Tl4Al12Si24O72•20(H2O) P 6/mmm 6/m 2/m 2/m

77.01.03.09 Paulingite-K (K2,Ca,Na2,Ba)5Al10Si35O90•45(H2O) Im3m 4/m 3 2/m

77.01.03.09a Paulingite-Na! (Na2,K2,Ca,Ba)5Al10Si35O90•45(H2O) Im3m 4/m 3 2/m

77.01.03.09b Paulingite-Ca! (Ca,K,Na,Ba)5[Al10Si35O84]•34(H2O) Im3m 4/m 3 2/m

77.01.03.10 Mazzite-Mg K2CaMg2(Al,Si)36O72•28(H2O) P 6₃/mmc 6/m 2/m 2/m

77.01.03.10a Mazzite-Na! Na8Al8Si28O72•30H2O P 6₃/mmc 6/m 2/m 2/m

77.01.03.11 Merlinoite (K,Ca,Na,Ba)7Si23Al9O64•23(H2O) I mmm 2/m 2/m 2/m

77.01.03.12 Montesommaite (K,Na)9Al9Si23O64•10(H2O) F dd2 mm2

Strunz Class:

09.GC.25 09 - SILICATES (Germanates)

09.G - Tektosilicates with Zeolitic H2O

09.GC -Chains of doubly-connected 4-membered rings

09.GC.25 Perlialite K8Tl4Al12Si24O72•20(H2O) P 6/mmm 6/m 2/m 2/m

Other Perlialite Information

References:

PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Perlialite :
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
15 - WWW-MINCRYST

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Perlialite

K8Tl4Al12Si24O72•20(H2O)
Dana No: 77.01.03.08 Strunz No: 09.GC.25
Locality:

Notes:

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