Thomasclarkite-(Y) Mineral Data

General Thomasclarkite-(Y) Information

Chemical Formula:

(Na,Ce)(Y,REE)(HCO3)(OH)3•4(H2O)

Composition:

Molecular Weight = 375.77 gm

Sodium 4.89 % Na 6.60 % Na₂O

Cerium 7.46 % Ce 8.73 % Ce₂O₃

La,Ce,Pr,Nd,Sm, 26.83 % RE 31.30 % REE₂O₃

Yttrium 11.83 % Y 15.02 % Y₂O₃

Hydrogen 3.22 % H 28.77 % H₂O

Carbon 3.20 % C 11.71 % CO₂

Oxygen 42.58 % O

______ ______

100.00 % 102.13 % = TOTAL OXIDE

Empirical Formula:

Na_0.8Ce_0.2Y_0.5REE_0.7(HCO₃)(OH)₃•4(H₂O)

Environment:

Occurs as a late hydrothermal phase in alkaline pegmatite dikes in nepheline syenite.

IMA Status:

Approved IMA 1998 (Dana # Added)

Locality:

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

Name Origin:

Named after Thomas Henry Clark (1893-1996), McGill University, Montreal, Quebec, Canada, noted for his studies of the geology of the St. Lawrence Lowlands.

Name Pronunciation:

Thomasclarkite-(Y) + Pronunciation

Synonym:

IMA1997-047

Thomasclarkite-(Y) Image

Images:

Thomasclarkite-(Y)

Comments: Transparent, yellowish crystal of thomasclarkite-(Y).
Location: Mt. St. Hilaire, Quebec, Canada. Scale: 0.75 mm.
© John Veevaert

Thomasclarkite-(Y) Crystallography

Axial Ratios:

a:b:c =0.3499:1:0.3507

Cell Dimensions:

a = 4.556, b = 13.018, c = 4.566, Z = 1; beta = 90.15° V = 270.81 Den(Calc)= 2.30

Crystal System:

Monoclinic - Sphenoidal H-M Symbol (2) Space Group: P 2

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

By Intensity(I/I_o): 12.97(1), 3.133(0.5), 4.32(0.5),

Physical Properties of Thomasclarkite-(Y)

Cleavage:

{010} Perfect, {101} Parting

Color:

White, Yellow.

Density:

2.3

Diaphaneity:

Translucent to transparent

Fracture:

Brittle - Uneven - Very brittle fracture producing uneven fragments.

Habit:

Pseudo Tetragonal - Crystals show a tetragonal shape.

Hardness:

2-3 - Gypsum-Calcite

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Thomasclarkite-(Y)

Gladstone-Dale:

CI meas= 0.045 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= 0.045 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2043,KPDmeas= 0.2043,KC= 0.214
Ncalc = 1.49

Optical Data:

Uniaxial (-), e=1.4, w=1.54, bire=0.1400.

Calculated Properties of Thomasclarkite-(Y)

Electron Density:

Bulk Density (Electron Density)=2.21 gm/cc
note: Specific Gravity of Thomasclarkite-(Y) =2.30 gm/cc.

Fermion Index:

Fermion Index = 0.05
Boson Index = 0.95

Photoelectric:

PE_{Thomasclarkite-(Y)}= 208.57 barns/electron
U=PE_{Thomasclarkite-(Y)} x r_electron= 461.12 barns/cc.

Radioactivity:

GRapi = 35,249.13 (Gamma Ray American Petroleum Institute Units)
Concentration of Thomasclarkite-(Y) per GRapi unit = 28.37 (PPM)

Thomasclarkite-(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) 862.91 ±215.73 grams of pure Thomasclarkite-(Y) .

**Estimated Radioactivity from Thomasclarkite-(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 / 9.40 cm	770,087	2.08E-05	35,249.13	11.59
100 gm / 4.36 cm	77,009	2.08E-06	3,524.91	1.16
10 gm / 2.02 cm	7,701	2.08E-07	352.49	0.12
1 gm / 9.40 mm	770	2.08E-08	35.25	0.01
0.1 gm / 4.36 mm	77	2.08E-09	3.52	0.00
0.01 gm / 2.02 mm	8	2.08E-10	0.35	0.00
0.001 gm / 0.94 mm	1	2.08E-11	0.04	0.00

Weight of pure Thomasclarkite-(Y) in grams (gm) and Calculated Diameter of a Sphere with a Density of 2.30 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 ( 1.71 % Th) From Sum REE Elements (34.28 % REE)

Thomasclarkite-(Y) Classification

Dana Class:

13.01.09.01 (13)Acid Carbonates

(13.01)with miscellaneous formulae

(13.01.09)Dana Group

13.01.09.01 Thomasclarkite-(Y)! (Na,Ce)(Y,REE)(HCO3)(OH)3•4(H2O) P 2 2

Strunz Class:

05.DC.20 05 - CARBONATES (NITRATES)

05.D - Carbonates with Additional Anions, with H2O

05.DC -With large cations

05.DC.20 Thomasclarkite-(Y)! (Na,Ce)(Y,REE)(HCO3)(OH)3•4(H2O) P 2 2

Other Thomasclarkite-(Y) Information

References:

NAME( CanMin, 8/99) PHYS. PROP.(Eur. J. Min.,Vol.10,1998) OPTIC PROP.(AmMin, v84, p1466)

See Also:

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

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Print or Cut-and-Paste your Thomasclarkite-(Y) Specimen Label here :

Thomasclarkite-(Y)

(Na,Ce)(Y,REE)(HCO3)(OH)3•4(H2O)
Dana No: 13.01.09.01 Strunz No: 05.DC.20
Locality:

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