Monazite-(Sm) Mineral Data

General Monazite-(Sm) Information

Chemical Formula:

SmPO4

Composition:

Molecular Weight = 221.25 gm

Calcium 1.81 % Ca 2.53 % CaO

Cerium 9.50 % Ce 11.13 % Ce₂O₃

Samarium 13.59 % Sm 15.76 % Sm₂O₃

Gadolinium 14.21 % Gd 16.38 % Gd₂O₃

Thorium 15.73 % Th 17.90 % ThO₂

Phosphorus 12.60 % P 28.87 % P₂O₅

Neodymium 6.52 % Nd 7.60 % Nd₂O₃

Oxygen 26.03 % O

______ ______

100.00 % 100.18 % = TOTAL OXIDE

Empirical Formula:

Sm_0.2Gd_0.2Th_0.15Ce_0.15Ca_0.1Nd_0.1(PO₄)_0.9

Environment:

Lepidolite-subtype granitic pegmatite within the Greer Lake intrusion of pegmatitic leucogranite. Monazite group, structure

IMA Status:

Approved IMA 2002 (Dana # Added)

Locality:

Anne Claim #3, 1.2 km northwest of Greer Lake, southeatern Mintoba, Canada. Link to MinDat.org Location Data.

Name Origin:

Named as the Sm-dominant member of the monazite series.

Name Pronunciation:

Monazite-(Sm)

Synonym:

ICSD 79751

IMA2001-001

PDF 46-1329

Monazite-(Sm) Image

Images:

Monazite-(Sm)

Comments: Back-scattered electron image of the main aggregate of monazite-(Sm) and manganocolumbite (C) embedded in quartz (black). Variations in brightness of the monazite-(Sm) are controlled by the Th content, whereas the ratio Nb/Ta affects manganotantalite.
Location: Annie Claim #3 pod, Greer Lake intrusion, Archean Bird River Subprovince of the Superior Province, Southeastern Manitoba, Canada. Scale: Grain size 0.8 mm.
© Canadian Mineralogist

Monazite-(Sm) Crystallography

Axial Ratios:

a:b:c =0.9695:1:0.9296

Cell Dimensions:

a = 6.725, b = 6.936, c = 6.448, Z = 4; beta = 104.02° V = 291.80 Den(Calc)= 5.04

Crystal System:

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

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

By Intensity(I/I_o): 3.065(1)(120), 2.857(0.9)(112,012), 4.162(0.8)(111),3.264(0.7)(200), 4.647(0.5)(011), 3.492(0.4)(111,020), 5.19(0.4),

Physical Properties of Monazite-(Sm)

Cleavage:

{???} Good

Color:

Yellowish.

Diaphaneity:

Translucent to transparent

Fracture:

Brittle - Uneven - Very brittle fracture producing uneven fragments.

Habit:

Platy - Sheet forms (e.g. micas).

Habit:

Subhedral Crystals - Occurs as crystals which tend to exhibit a recognizable crystal shape.

Luster:

Vitreous - Greasy

Streak:

white

Optical Properties of Monazite-(Sm)

Gladstone-Dale:

CI calc= -0.005 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1559,KC= 0.1551
Ncalc = 1.78

Optical Data:

Biaxial (+), a=1.768, b=1.771, g=1.818, bire=0.0500

Calculated Properties of Monazite-(Sm)

Electron Density:

Bulk Density (Electron Density)=4.45 gm/cc
note: Specific Gravity of Monazite-(Sm) =5.04 gm/cc.

Fermion Index:

Fermion Index = 0.15
Boson Index = 0.85

Photoelectric:

PE_{Monazite-(Sm)}= 658.05 barns/electron
U=PE_{Monazite-(Sm)} x r_electron=2,929.09 barns/cc.

Radioactivity:

GRapi = 297,115.85 (Gamma Ray American Petroleum Institute Units)
Concentration of Monazite-(Sm) per GRapi unit = 3.37 (PPM)

Monazite-(Sm) 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) 102.37 ± 25.59 grams of pure Monazite-(Sm) .

**Estimated Radioactivity from Monazite-(Sm)** - strong
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 / 7.24 cm	7,064,896	1.91E-04	297,115.85	97.68
100 gm / 3.36 cm	706,490	1.91E-05	29,711.58	9.77
10 gm / 1.56 cm	70,649	1.91E-06	2,971.16	0.98
1 gm / 7.24 mm	7,065	1.91E-07	297.12	0.10
0.1 gm / 3.36 mm	706	1.91E-08	29.71	0.01
0.01 gm / 1.56 mm	71	1.91E-09	2.97	0.00
0.001 gm / 0.72 mm	7	1.91E-10	0.30	0.00

Weight of pure Monazite-(Sm) in grams (gm) and Calculated Diameter of a Sphere with a Density of 5.04 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

Monazite-(Sm) Classification

Dana Class:

38.04.03.07 (38)Anhydrous Phosphates, etc

(38.04)A+ XO4

(38.04.03)Monazite Group (Monoclinic: P21/n)

38.04.03.01 Monazite-(Ce) (Ce,La,Nd,Th)PO4 P 2₁/n 2/m

38.04.03.02 Monazite-(La) (La,Ce,Nd)PO4 P 2₁/n 2/m

38.04.03.03 Cheralite-(Ce)? (Ce,Ca,Th)(P,Si)O4 P 2₁/n 2/m

38.04.03.04 Brabantite? CaTh(PO4)2 P 2₁ 2

38.04.03.05 Monazite-(Nd) (Nd,Ce,La)(P,Si)O4 P 2₁/n 2/m

38.04.03.06 Gasparite-(Ce) CeAsO4 P 2₁/n 2/m

38.04.03.07 Monazite-(Sm)! SmPO4 P 2₁/n 2/m

Strunz Class:

08.AD.50 08 - PHOSPHATES, ARSENATES, VANADATES

08.A - Phosphates, etc. without additional anions, without H2O

08.AD -With only large cations

08.AD.50 Brabantite? CaTh(PO4)2 P 2₁ 2

08.AD.50 Gasparite-(Ce) CeAsO4 P 2₁/n 2/m

08.AD.50 Monazite-(Ce) (Ce,La,Nd,Th)PO4 P 2₁/n 2/m

08.AD.50 Monazite-(La) (La,Ce,Nd)PO4 P 2₁/n 2/m

08.AD.50 Monazite-(Nd) (Nd,Ce,La)(P,Si)O4 P 2₁/n 2/m

08.AD.50 Rooseveltite BiAsO4 P 2/m 2/m

08.AD.50 Monazite-(Sm)! SmPO4 P 2₁/n 2/m

Other Monazite-(Sm) Information

References:

NAME( CanMin, v 41, p 820) PHYS. PROP.(CanMin, v 41, p 820) OPTIC PROP.(CanMin, v 41, p 820)

See Also:

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

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Print or Cut-and-Paste your Monazite-(Sm) Specimen Label here :

Monazite-(Sm)

SmPO4
Dana No: 38.04.03.07 Strunz No: 08.AD.50
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