Milarite Mineral Data

General Milarite Information

Chemical Formula:

K2Ca4Al2Be4Si24O60•(H2O)

Composition:

Molecular Weight = 1,980.55 gm

Potassium 3.95 % K 4.76 % K₂O

Calcium 8.09 % Ca 11.33 % CaO

Beryllium 1.82 % Be 5.05 % BeO

Aluminum 2.72 % Al 5.15 % Al₂O₃

Silicon 34.03 % Si 72.81 % SiO₂

Hydrogen 0.10 % H 0.91 % H₂O

Oxygen 49.28 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

K₂Ca₄Al₂Be₄(Si₂₄O₆₀)•(H₂O)

Environment:

Granitic pegmatites.

IMA Status:

Valid Species (Pre-IMA) 1870

Locality:

Val Milar, Switzerland. Link to MinDat.org Location Data.

Name Origin:

Named after its locality.

Name Pronunciation:

Milarite

Synonym:

ICSD 6260

PDF 35-459

Milarite Image

Images:

Milarite

Comments: Single transparent crystal of yellow Milarite.
Location: Near Rossing, Namibia. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

Images:

Milarite

Comments: Blocky, barrel-shaped crystal of milarite on muscovite..
Location: Jagauaracu, Minas Gerais, Brazil. Scale: Crystal size 2.5 x 1 x 1 cm.
© Rob Lavinsky

Milarite Crystallography

Axial Ratios:

a:c = 1:1.32997

Cell Dimensions:

a = 10.41, c = 13.845, Z = 1; V = 1,299.35 Den(Calc)= 2.53

Crystal System:

Hexagonal - Dihexagonal DipyramidalH-M Symbol (6/m 2/m 2/m) Space Group: P 6/mcc

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

By Intensity(I/I_o): 3.307(1), 2.88(0.9), 4.16(0.65),

Crystal Structure:

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Hawthorne F C , Kimata M , Cerny P , Ball N A , Rossman G R , Grice J D , American Mineralogist , 76 (1991) p.1836-1856, The crystal chemistry of the milarite-group minerals, sample #25 from Guanajuato, Note: U(1,2) of WatB/NaB changed to match symmetry constraints

View Additional jPOWD Structure files for Milarite
[1] [10] [2] [3] [4] [5] [6] [7] [8] [9]

Physical Properties of Milarite

Cleavage:

{0001} Imperfect, {1120} Imperfect

Color:

Colorless, White, Greenish white, Yellowish white.

Density:

2.52

Diaphaneity:

Transparent to translucent

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Habit:

Crystalline - Coarse - Occurs as well-formed coarse sized crystals.

Habit:

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

Habit:

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

Hardness:

6 - Orthoclase

Luminescence:

Fluorescent, Short UV=bluish white.

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Milarite

Dichroism (e):

colorless.

Dichroism (w):

colorless.

Gladstone-Dale:

CI meas= -0.013 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.009 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2124,KPDmeas= 0.2132,KC= 0.2104
Ncalc = 1.53

Optical Data:

Uniaxial (-), e=1.529-1.548, w=1.532-1.551, bire=0.0030-0.0160.

Calculated Properties of Milarite

Electron Density:

Bulk Density (Electron Density)=2.52 gm/cc
note: Specific Gravity of Milarite =2.53 gm/cc.

Fermion Index:

Fermion Index = 0.03
Boson Index = 0.97

Photoelectric:

PE_Milarite= 2.79 barns/electron
U=PE_Milarite x r_electron= 7.04 barns/cc.

Radioactivity:

GRapi = 56.71 (Gamma Ray American Petroleum Institute Units)
Concentration of Milarite per GRapi unit = 1.76 (%)

Estimated Radioactivity from Milarite - barely detectable

Milarite Classification

Dana Class:

63.02.01a.12 (63)Cyclosilicate Condensed Rings

(63.02)6-membered rings

(63.02.01a)Milarite - Osumilite group (Milarite - Osumilite subgroup)

63.02.01a.01 Brannockite KSn2Li3Si12O30 P 6/mcc 6/m 2/m 2/m

63.02.01a.02 Chayesite K(Mg,Fe)4Fe(Si12O30) P 6/mcc 6/m 2/m 2/m

63.02.01a.03 Darapiosite KNa2Zr[Li(Mn,Zr)2Si12O30] P 6/mcc 6/m 2/m 2/m

63.02.01a.04 Eifelite KNa3Mg4Si12O30 P 6/mcc 6/m 2/m 2/m

63.02.01a.05 Merrihueite (K,Na)2(Fe,Mg)5Si12O30 P 6/mcc 6/m 2/m 2/m

63.02.01a.06 Osumilite-(Fe) (K,Na)(Fe,Mg)2(Al,Fe)3(Si,Al)12O30 P 6/mcc 6/m 2/m 2/m

63.02.01a.07 Osumilite-(Mg) (K,Na)(Mg,Fe)2(Al,Fe)3(Si,Al)12O30 P 6/mcc 6/m 2/m 2/m

63.02.01a.08 Poudretteite KNa2B3Si12O30 P 6/mcc 6/m 2/m 2/m

63.02.01a.09 Sugilite KNa2(Fe,Mn,Al)2Li3Si12O30 P 6/mcc 6/m 2/m 2/m

63.02.01a.10 Yagiite (Na,K)3Mg4(Al,Mg)6(Si,Al)24O60 P 6/mmc 6/m 2/m 2/m

63.02.01a.11 Dusmatovite K(K,Na,[])(Mn,Y,Zr)2(Zn,Li)3Si12O30 P 6/mcc 6/m 2/m 2/m

63.02.01a.12 Milarite K2Ca4Al2Be4Si24O60•(H2O) P 6/mcc 6/m 2/m 2/m

63.02.01a.13 Sogdianite (K,Na)2(Li,Fe,Al)3ZrSi12O30 P 6/mmm 6/m 2/m 2/m

63.02.01a.14 Roedderite (Na,K)2(Mg,Fe)5Si12O30 P 6₃/mmc 6/m 2/m 2/m

63.02.01a.15 Berezanskite! KLi3Ti2Si12O30 P 6/mcc 6/m 2/m 2/m

63.02.01a.16 Shibkovite! K(Ca,Mn,Na)2(K2-x,[]x)2ZnSi12O30(x~0.8) P 6/mcc 6/m 2/m 2/m

63.02.01a.17 Trattnerite! (Fe,Mg)2(Mg,Fe)3(Si12O30) P 6/mcc 6/m 2/m 2/m

63.02.01a.18 Almarudite! K([],Na)2(Mn,Fe,Mg)2(Be,Al)3[Si12O30] P 6/mcc 6/m 2/m 2/m

63.02.01a.19 Oftedalite! (Sc,Ca)2KBe3Si12O30 P 6/mmc 6/m 2/m 2/m

63.02.01a.20 Klochite ([]1Na1)KFe2Zn3[Si12O30] P 6/mcc 6/m 2/m 2/m

63.02.01a.21 Friedrichbeckeite! K([],Na)Mg2(Be2Mg)Si12O30 P 6/mcc 6/m 2/m 2/m

Strunz Class:

09.CM.05 09 - SILICATES (Germanates)

09.C - Cyclosilicates

09.CM -[Si6O18]12- 6-membered double rings (sechser-Doppelringe)

09.CM.05 Brannockite KSn2Li3Si12O30 P 6/mcc 6/m 2/m 2/m

09.CM.05 Armenite BaCa2Al6Si9O30•2(H2O) Pnc2 mm2

09.CM.05 Berezanskite! KLi3Ti2Si12O30 P 6/mcc 6/m 2/m 2/m

09.CM.05 Dusmatovite K(K,Na,[])(Mn,Y,Zr)2(Zn,Li)3Si12O30 P 6/mcc 6/m 2/m 2/m

09.CM.05 Chayesite K(Mg,Fe)4Fe(Si12O30) P 6/mcc 6/m 2/m 2/m

09.CM.05 Shibkovite! K(Ca,Mn,Na)2(K2-x,[]x)2ZnSi12O30(x~0.8) P 6/mcc 6/m 2/m 2/m

09.CM.05 Eifelite KNa3Mg4Si12O30 P 6/mcc 6/m 2/m 2/m

09.CM.05 Darapiosite KNa2Zr[Li(Mn,Zr)2Si12O30] P 6/mcc 6/m 2/m 2/m

09.CM.05 Merrihueite (K,Na)2(Fe,Mg)5Si12O30 P 6/mcc 6/m 2/m 2/m

09.CM.05 Roedderite (Na,K)2(Mg,Fe)5Si12O30 P 6₃/mmc 6/m 2/m 2/m

09.CM.05 Milarite K2Ca4Al2Be4Si24O60•(H2O) P 6/mcc 6/m 2/m 2/m

09.CM.05 Osumilite-(Fe) (K,Na)(Fe,Mg)2(Al,Fe)3(Si,Al)12O30 P 6/mcc 6/m 2/m 2/m

09.CM.05 Osumilite-(Mg) (K,Na)(Mg,Fe)2(Al,Fe)3(Si,Al)12O30 P 6/mcc 6/m 2/m 2/m

09.CM.05 Poudretteite KNa2B3Si12O30 P 6/mcc 6/m 2/m 2/m

09.CM.05 Sugilite KNa2(Fe,Mn,Al)2Li3Si12O30 P 6/mcc 6/m 2/m 2/m

09.CM.05 Sogdianite (K,Na)2(Li,Fe,Al)3ZrSi12O30 P 6/mmm 6/m 2/m 2/m

09.CM.05 Oftedalite! (Sc,Ca)2KBe3Si12O30 P 6/mmc 6/m 2/m 2/m

09.CM.05 Yagiite (Na,K)3Mg4(Al,Mg)6(Si,Al)24O60 P 6/mmc 6/m 2/m 2/m

09.CM.05 Trattnerite! (Fe,Mg)2(Mg,Fe)3(Si12O30) P 6/mcc 6/m 2/m 2/m

09.CM.05 Almarudite! K([],Na)2(Mn,Fe,Mg)2(Be,Al)3[Si12O30] P 6/mcc 6/m 2/m 2/m

Other Milarite Information

References:

NAME( Duda&Rejl90) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990;www.saint-hilaire.ca) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Milarite :
1 - Alkali-Nuts(English)
2 - Alkali-Nuts(Francais)
3 - Am. Min. Crystal Structure Database
4 - Amethyst Galleries' Mineral Gallery
5 - Athena
6 - EUROmin Project
7 - Ecole des Mines de Paris
8 - GeoScienceWorld
9 - Google Images
10 - Google Scholar
11 - Handbook of Mineralogy (MinSocAm)
12 - Handbook of Mineralogy (UofA)
13 - MinDAT
14 - Mineralienatlas (Deutsch)
15 - Online Mineral Museum
16 - QUT Mineral Atlas
17 - Ruff.Info
18 - WWW-MINCRYST

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

Milarite

K2Ca4Al2Be4Si24O60•(H2O)
Dana No: 63.02.01a.12 Strunz No: 09.CM.05
Locality:

Notes: