Thorbastnasite Mineral Data

General Thorbastnasite Information

Chemical Formula:

Th(Ca,Ce)(CO3)2F2•3(H2O)

Composition:

Molecular Weight = 509.19 gm

Calcium 5.90 % Ca 8.26 % CaO

Cerium 6.88 % Ce 8.06 % Ce₂O₃

Thorium 45.57 % Th 51.85 % ThO₂

Hydrogen 1.19 % H 10.61 % H₂O

Carbon 4.72 % C 17.29 % CO₂

Oxygen 28.28 % O

Fluorine 7.46 % F 7.46 % F

- % F -3.14 % -O=F₂

______ ______

100.00 % 100.39 % = TOTAL OXIDE

Empirical Formula:

ThCa_0.75Ce_0.25(CO₃)₂F₂•3(H₂O)

Environment:

Metasomatic albitite and quartz–muscovite veinlets in an alkaline exocontact surrounding a syenite intrusive.

IMA Status:

Approved IMA 1965

Locality:

Pichikhol alkaline massif, Balygtyg-Khem River, Sangilen Upland, Tuva, Siberia, Russia. Link to MinDat.org Location Data.

Name Origin:

Named for a thorium-bearing mineral chemically similar to bastnasite.

Name Pronunciation:

Thorbastnasite + Pronunciation

Synonym:

Thorbastnaesite

Thorbastnasite Image

Images:

Click Here for Larger Thorbastnasite Image

Thorbastnasite Rontgenite-(Ce)

Comments: Tny white, acicular thorbastnasite crystals to less than 1 mm in sprays. The thorbastnasite forms the cores the 'needles', with white epitaxial rontgenite-(Ce) coating.
Location: Mont Saint-Hilaire, Quebec, Canada. Scale: Needle Size < 1 mm.
© William Lechner / Dakota Matrix

Thorbastnasite Crystallography

Axial Ratios:

a:c = 1:1.38912

Cell Dimensions:

a = 6.99, c = 9.71, Z = 2; V = 410.87 Den(Calc)= 4.12

Crystal System:

Hexagonal - Ditrigonal DipyramidalH-M Symbol (6 m2) Space Group: P 62c

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

By Intensity(I/I_o): 2.03(1), 2.85(1), 3.54(0.8),

Physical Properties of Thorbastnasite

Color:

Brown.

Density:

4.04

Diaphaneity:

Translucent

Hardness:

4-4.5 - Between Fluorite and Apatite

Luster:

Vitreous - Greasy

Optical Properties of Thorbastnasite

Gladstone-Dale:

CI meas= 0.129 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.146 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1636,KPDmeas= 0.1668,KC= 0.1916
Ncalc = 1.77 - 1.79

Optical Data:

Uniaxial (+), e=1.67-1.678.

Calculated Properties of Thorbastnasite

Electron Density:

Bulk Density (Electron Density)=3.61 gm/cc
note: Specific Gravity of Thorbastnasite =4.04 gm/cc.

Fermion Index:

Fermion Index = 0.0007366213
Boson Index = 0.9992633787

Photoelectric:

PE_{Thorbastnasite}=1,109.22 barns/electron
U=PE_{Thorbastnasite} x r_electron=4,004.38 barns/cc.

Radioactivity:

GRapi = 868,712.05 (Gamma Ray American Petroleum Institute Units)
Concentration of Thorbastnasite per GRapi unit =1,151.13 (PPB)

Thorbastnasite 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) 35.01 ± 8.75 grams of pure Thorbastnasite .
Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 100 cm box) 3501.4 ±875.34 grams of pure Thorbastnasite .

**Estimated Radioactivity from Thorbastnasite** - strong
Specimen Size Weight/Volume (Sphere) *	Calculated Activity Becquerels (Bq)	Calculated Activity Curies (Ci)	Estimated Activity GR(api)	Estimated Exposure (mRem**)/hr If Held in Hand For One Hour
1000 gm / 7.79 cm	20,415,524	5.52E-04	868,712.05	285.60
100 gm / 3.62 cm	2,041,552	5.52E-05	86,871.21	28.56
10 gm / 1.68 cm	204,155	5.52E-06	8,687.12	2.86
1 gm / 7.79 mm	20,416	5.52E-07	868.71	0.29
0.1 gm / 3.62 mm	2,042	5.52E-08	86.87	0.03
0.01 gm / 1.68 mm	204	5.52E-09	8.69	0.00
0.001 gm / 0.78 mm	20	5.52E-10	0.87	0.00

Weight of pure Thorbastnasite in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.04 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

Thorbastnasite Classification

Dana Class:

16b.01.02.01 (16b)Carbonates - Hydroxyl or Halogen

(16b.01)where (A)m (B)n (XO3)p Zq, with (m+n):p=1:1

(16b.01.02)Dana Group

16b.01.02.01 Thorbastnasite Th(Ca,Ce)(CO3)2F2•3(H2O) P 62c 6 m2

Strunz Class:

05.BD.20a 05 - CARBONATES (NITRATES)

05.B - Carbonates with additional anions, without H2O

05.BD -With rare-earth elements (REE)

05.BD.20a Bastnasite-(Ce) Ce(CO3)F P 62c 6 m2

05.BD.20a Bastnasite-(La) La(CO3)F P 62c 6 m2

05.BD.20a Bastnasite-(Y) Y(CO3)F P 62c 6 m2

05.BD.20a Hydroxylbastnasite-(Ce) Ce(CO3)(OH) P 62c 6 m2

05.BD.20a Hydroxylbastnasite-(La) La(CO3)(OH) C 222₁ 2 2 2

05.BD.20a Hydroxylbastnasite-(Nd) Nd(CO3)(OH) P 62c 6 m2

05.BD.20a Thorbastnasite Th(Ca,Ce)(CO3)2F2•3(H2O) P 62c 6 m2

Other Thorbastnasite Information

References:

NAME( AntBidBlaNic3) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Thorbastnasite :
1 - Alkali-Nuts(English)
2 - Am. Min. Crystal Structure Database
3 - Athena
4 - GeoScienceWorld
5 - Google Images
6 - Google Scholar
7 - Handbook of Mineralogy (MinSocAm)
8 - Handbook of Mineralogy (UofA)
9 - MinDAT
10 - Mineralienatlas (Deutsch)
11 - Online Mineral Museum
12 - QUT Mineral Atlas
13 - Ruff.Info
14 - Uranium Minerals

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

Thorbastnasite

Th(Ca,Ce)(CO3)2F2•3(H2O)
Dana No: 16b.01.02.01 Strunz No: 05.BD.20a
Locality:

Notes: