Vyuntspakhkite-(Y) Mineral Data

General Vyuntspakhkite-(Y) Information

Chemical Formula:

(Y,Yb,Er)4Al2AlSi5O18(OH)5

Composition:

Molecular Weight = 1,118.90 gm

La,Ce,Pr,Nd,Sm, 12.61 % RE 14.71 % REE₂O₃

Yttrium 14.14 % Y 17.96 % Y₂O₃

Ytterbium 20.26 % Yb 23.07 % Yb₂O₃

Aluminum 7.31 % Al 13.81 % Al₂O₃

Silicon 12.40 % Si 26.53 % SiO₂

Hydrogen 0.45 % H 3.99 % H₂O

Oxygen 32.83 % O

______ ______

100.00 % 100.07 % = TOTAL OXIDE

Empirical Formula:

Y_1.78Yb_1.31REE_0.98Al_3.03Si_4.94O₁₈(OH)_4.96

Environment:

Two generations of crystals occur in fluorite in "amazonite" pegmatites.

IMA Status:

Approved IMA 1987

Locality:

Mt. Vyuntspakhk, 5 km southeast of Mt. Ploskaya, Kola Peninsula, Russia. Link to MinDat.org Location Data.

Name Origin:

Named for the locality and its yttrium content.

Name Pronunciation:

Vyuntspakhkite-(Y) + Pronunciation

Synonym:

ICSD 20861

PDF 35-708

Vyuntspakhkite-(Y) Crystallography

Axial Ratios:

a:b:c =0.3949:1:0.421

Cell Dimensions:

a = 5.83, b = 14.763, c = 6.216, Z = 1; beta = 123.05° V = 448.43 Den(Calc)= 4.14

Crystal System:

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

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

By Intensity(I/I_o): 3.47(1), 2.604(0.8), 7.4(0.6),

Physical Properties of Vyuntspakhkite-(Y)

Cleavage:

None

Color:

Colorless, Orange.

Density:

4.02

Diaphaneity:

Transparent

Fracture:

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

Habit:

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

Hardness:

6-7 - Orthoclase-Quartz

Luminescence:

Cathodoluminescence, Short UV=faint yellow green.

Luster:

Adamantine

Streak:

white

Optical Properties of Vyuntspakhkite-(Y)

Gladstone-Dale:

CI meas= -0.018 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.011 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1684,KPDmeas= 0.1735,KC= 0.1703
Ncalc = 1.68 - 1.71

Optical Data:

Biaxial (+), a=1.68, b=1.692, g=1.72, bire=0.0400, 2V(Calc)=68, 2V(Meas)=68.

Calculated Properties of Vyuntspakhkite-(Y)

Electron Density:

Bulk Density (Electron Density)=3.83 gm/cc
note: Specific Gravity of Vyuntspakhkite-(Y) =4.14 gm/cc.

Fermion Index:

Fermion Index = 0.09
Boson Index = 0.91

Photoelectric:

PE_{Vyuntspakhkite-(Y)}= 290.04 barns/electron
U=PE_{Vyuntspakhkite-(Y)} x r_electron=1,112.00 barns/cc.

Radioactivity:

GRapi = 32,515.92 (Gamma Ray American Petroleum Institute Units)
Concentration of Vyuntspakhkite-(Y) per GRapi unit = 30.75 (PPM)

Vyuntspakhkite-(Y) is Radioactive as defined in 49 CFR 173.403. Greater than 70 Bq / gram.

Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 10 cm box) 935.44 ±233.86 grams of pure Vyuntspakhkite-(Y) .

**Estimated Radioactivity from Vyuntspakhkite-(Y)** - weak
Specimen Size Weight/Volume (Sphere) *	Calculated Activity Bequerols (Bq)	Calculated Activity Curies (Ci)	Estimated Activity GR(api)	Estimated Exposure (mRem**)/hr If Held in Hand For One Hour
1000 gm / 7.73 cm	737,344	1.99E-05	32,515.92	10.69
100 gm / 3.59 cm	73,734	1.99E-06	3,251.59	1.07
10 gm / 1.66 cm	7,373	1.99E-07	325.16	0.11
1 gm / 7.73 mm	737	1.99E-08	32.52	0.01
0.1 gm / 3.59 mm	74	1.99E-09	3.25	0.00
0.01 gm / 1.66 mm	7	1.99E-10	0.33	0.00
0.001 gm / 0.77 mm	1	1.99E-11	0.03	0.00

Weight of pure Vyuntspakhkite-(Y) in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.14 gm/cc.*
Goverment Estimate of Average Annual Exposure ( 360 mRem) **
Note: 10 microsieverts/hr = 1 mRem/hr **
Max Permissable Adult Dose 50,000 mRem/yr (hands), 15,000 mRem/yr (eyes)
Lethal Dose LD(50) Exposure 400,000 to 500,000 mRem
Estimated Thorium Activity ( 1.64 % Th) From Sum REE Elements (32.87 % REE)

Vyuntspakhkite-(Y) Classification

Dana Class:

78.07.18.01 (78)Unclassified silicates

(78.07)wholly unclassified silicates

(78.07.18)Dana Group

78.07.18.01 Vyuntspakhkite-(Y) (Y,Yb,Er)4Al2AlSi5O18(OH)5 P 2₁/c 2/m

Strunz Class:

09.BG.40 09 - SILICATES (Germanates)

09.B - Sorosilicates

09.BG -Sorosilicates with mixed SiO4 and Si2O7 groups;

09.BG.40 Vyuntspakhkite-(Y) (Y,Yb,Er)4Al2AlSi5O18(OH)5 P 2₁/c 2/m

Other Vyuntspakhkite-(Y) Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Vyuntspakhkite-(Y) :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - GeoScienceWorld
5 - Google Images
6 - Google Scholar
7 - Handbook of Mineralogy (UofA)
8 - MinDAT
9 - Mineralienatlas (Deutsch)
10 - Online Mineral Museum
11 - QUT Mineral Atlas
12 - Ruff.Info
13 - WWW-MINCRYST

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Vyuntspakhkite-(Y)

(Y,Yb,Er)4Al2AlSi5O18(OH)5
Dana No: 78.07.18.01 Strunz No: 09.BG.40
Locality:

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