Monteregianite-(Y) Mineral Data

General Monteregianite-(Y) Information

Chemical Formula:

(Na,K)6(Y,Ca)2Si16O38•10(H2O)

Composition:

Molecular Weight = 1,574.86 gm

Potassium 4.47 % K 5.38 % K₂O

Sodium 6.86 % Na 9.25 % Na₂O

Calcium 0.51 % Ca 0.71 % CaO

Yttrium 9.60 % Y 12.19 % Y₂O₃

Aluminum 0.34 % Al 0.65 % Al₂O₃

Silicon 28.18 % Si 60.28 % SiO₂

Hydrogen 1.28 % H 11.44 % H₂O

Oxygen 48.76 % O

______ ______

100.00 % 99.90 % = TOTAL OXIDE

Empirical Formula:

K_1.8Na_4.7Y_1.7Ca_0.2Si_15.8Al_0.2O₃₈•10(H₂O)

Environment:

In miarolitic cavities, metamorphosed inclusions in nepheline syenite.

IMA Status:

Approved IMA 1987

Locality:

Mont Saint-Hilaire, Quebec, Canada. Link to MinDat.org Location Data.

Name Origin:

Named for the Monteregian Hills, a series of intrusions.

Name Pronunciation:

Monteregianite-(Y) + Pronunciation

Synonym:

ICSD 202257

IMA1972-026

PDF 31-1087

Monteregianite-(Y) Image

Images:

Monteregianite-(Y)

Comments: Feathery, radiating pinkish-white acicular monteregianite crystals on one end of greenish matrix.
Location: Desourdy Quarry, Mont Saint-Hilaire, Quebec, Canada. Scale: Specimen Size 5x2.5x2.5 cm..
© John Betts - Fine Minerals

Monteregianite-(Y) Crystallography

Axial Ratios:

a:b:c =0.397:1:0.4014

Cell Dimensions:

a = 9.512, b = 23.956, c = 9.617, Z = 2; beta = 93.85° V = 2,186.47 Den(Calc)= 2.39

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 2₁/m

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

By Intensity(I/I_o): 4.42(1), 7.03(1), 12(1),

Physical Properties of Monteregianite-(Y)

Cleavage:

{010} Perfect, {001} Good, {100} Distinct

Color:

Colorless, Greenish, Gray, Gray white, White.

Density:

2.42

Diaphaneity:

Transparent to Translucent

Habit:

Acicular - Occurs as needle-like crystals.

Habit:

Pseudo Orthorhombic - Crystals show an orthorhombic shape.

Habit:

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

Hardness:

3.5 - Copper Penny

Luminescence:

Fluorescent, Short UV=green.

Luster:

Vitreous - Silky

Streak:

white

Optical Properties of Monteregianite-(Y)

Gladstone-Dale:

CI meas= 0.018 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.005 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2148,KPDmeas= 0.2121,KC= 0.216
Ncalc = 1.52

Optical Data:

Biaxial (+), a=1.51, b=1.513, g=1.517, bire=0.0070

Pleochroism (x):

colorless.

Pleochroism (y):

colorless.

Pleochroism (z):

colorless.

Calculated Properties of Monteregianite-(Y)

Electron Density:

Bulk Density (Electron Density)=2.38 gm/cc
note: Specific Gravity of Monteregianite-(Y) =2.39 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_{Monteregianite-(Y)}= 13.06 barns/electron
U=PE_{Monteregianite-(Y)} x r_electron= 31.07 barns/cc.

Radioactivity:

GRapi = 64.20 (Gamma Ray American Petroleum Institute Units)
Concentration of Monteregianite-(Y) per GRapi unit = 1.56 (%)

Estimated Radioactivity from Monteregianite-(Y) - barely detectable

Monteregianite-(Y) Classification

Dana Class:

72.05.01.02 (72)Phyllosilicate Two-Dimensional Infinite Sheets with Other Than Six-Membered Rings

(72.05)with corrugated and complex layers

(72.05.01)Rhodesite group

72.05.01.01 Rhodesite KHCa2Si8O19•5(H2O) Pmam 2/m 2/m 2/m

72.05.01.02 Monteregianite-(Y) (Na,K)6(Y,Ca)2Si16O38•10(H2O) P 2₁/m 2/m

72.05.01.03 Macdonaldite BaCa4[Si16O36(OH)2]•10(H2O) C mcm 2/m 2/m 2/m

72.05.01.04 Delhayelite (Na,K)10Ca5Al6Si32O80(Cl2,F2,SO4)3•18(H2O) Pnmm 2/m 2/m 2/m

72.05.01.05 Hydrodelhayelite KCa2AlSi7O17(OH)2•6(H2O) Pnm21 mm2

72.05.01.06 Seidite-(Ce)! Na4(Ce,Sr)2{Ti(OH)2(Si8O18)}(O,OH,F)4•5(H2O) C/2c 2/m

Strunz Class:

09.EB.15 09 - SILICATES (Germanates)

09.E - Phyllosilicates

09.EB -Double nets with 4- and 6-membered rings

09.EB.15 Monteregianite-(Y) (Na,K)6(Y,Ca)2Si16O38•10(H2O) P 2₁/m 2/m

Other Monteregianite-(Y) Information

References:

NAME( AntBidBlaNic2) 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 Monteregianite-(Y) :
1 - Alkali-Nuts(English)
2 - Alkali-Nuts(Francais)
3 - Am. Min. Crystal Structure Database
4 - Athena
5 - EUROmin Project
6 - GeoScienceWorld
7 - Google Images
8 - Google Scholar
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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Monteregianite-(Y)

(Na,K)6(Y,Ca)2Si16O38•10(H2O)
Dana No: 72.05.01.02 Strunz No: 09.EB.15
Locality:

Notes:

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