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Monazite-(La) Mineral Data

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General Monazite-(La) Information

Help on Chemical  Formula: Chemical Formula: (La,Ce,Nd)PO4
Help on Composition: Composition: Molecular Weight = 239.90 gm
   Lanthanum   28.95 %  La   33.95 % La2O3
   Cerium      14.60 %  Ce   17.10 % Ce2O3
   Thorium      4.84 %  Th    5.50 % ThO2
   Phosphorus  12.91 %  P    29.58 % P2O5
   Neodymium   12.02 %  Nd   14.03 % Nd2O3
   Oxygen      26.68 %  O
              ______        ______ 
              100.00 %      100.17 % = TOTAL OXIDE
Help on Empirical Formula: Empirical Formula: La0.5Ce0.25Nd0.2Th0.05(PO4)
Help on Environment: Environment: Granitic pegmatites.
Help on IMA Status: IMA Status: Approved IMA 1966
Help on Locality: Locality: Mars Hill, Madison County, North Carolina. Link to MinDat.org Location Data.
Help on Name Origin: Name Origin: From the Greek monazeis - "to be alone" in allusion to its isolated crystals and their rarity when first found.
Help on Name Pronunciation: Name Pronunciation: Monazite-(La) Say MONAZITE-(LA)
Help on Synonym: Synonym: ICSD 79747
  PDF 46-1326
 

Monazite-(La) Image

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  Monazite-(La)

Comments: Yellowish crystals of monazite-(La) in a cavity in nephelin-syenite pegmatite.
Location: Kuivchorr Mt, Lovozero Massif, Kola Peninsula, Murmanskaja Oblast', Northern Region, Russia. Scale: FOV is 9x7 mm.
© Pavel M. Kartashov

Monazite-(La) Crystallography

Help on Axial Ratios: Axial Ratios: a:b:c =0.9686:1:0.9215
Help on Cell Dimensions: Cell Dimensions: a = 6.79, b = 7.01, c = 6.46, Z = 4; beta = 103.633° V = 298.82 Den(Calc)= 5.33
Help on Crystal System: 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/Io): 3.12(1), 3.31(0.85), 2.15(0.4),
Help on Forms: Forms:

Mouse
Dbl Clk - Start-Stop Rotation
RMB - Cycle Display Modes
Drag1 - Manipulate Crystal
Drag2 - Resize

Keyboard
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I - Indicies
<space> - Start-Stop Rotation
F - Fit to Screen
M - Menu

Help on Above

Forms: ( 0 1 0) ( 1 1 1) ( 1 0 1) ( 1 1 0) ( 1 0 0) ( 1 0 1)

Warning: this java applet does not work in some browsers because of security restrictions.

 

Physical Properties of Monazite-(La)

Help on Cleavage: Cleavage: {001} Distinct, {100} Indistinct
Help on Color: Color: Brown, Brown, Yellowish brown, Pink, Yellow.
Help on Density: Density: 4.8 - 5.5, Average = 5.15
Help on Diaphaneity: Diaphaneity: Transparent to Subtranslucent
Help on Fracture: Fracture: Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).
Help on Habit: Habit: Crystalline - Fine - Occurs as well-formed fine sized crystals.
Help on Habit: Habit: Twinning Common - Crystals are usually twinned.
Help on Hardness: Hardness: 5-5.5 - Apatite-Knife Blade
Help on Luster: Luster: Adamantine - Resinous
Help on Streak: Streak: grayish white
 

Optical Properties of Monazite-(La)

Help on Gladstone-Dale: Gladstone-Dale: CI meas= 0.009 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.042 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1508,KPDmeas= 0.1561,KC= 0.1574
Ncalc = 1.76 - 1.87
Help on Optical Data: Optical Data: Biaxial (+), a=1.77-1.8, b=1.7705-1.802, g=1.83-1.85, bire=0.0500-0.0600, 2V(Calc)=12-24, 2V(Meas)=12.
 

Calculated Properties of Monazite-(La)

Help on Electron Density: Electron Density: Bulk Density (Electron Density)=4.57 gm/cc
note: Specific Gravity of Monazite-(La) =5.15 gm/cc.
Help on Fermion Index: Fermion Index: Fermion Index = 0.02
Boson Index = 0.98
Help on Photoelectric: Photoelectric: PEMonazite-(La) = 402.34 barns/electron
U=PEMonazite-(La) x relectron=1,839.70 barns/cc.
Help on Radioactivity: Radioactivity:

GRapi = 91,600.36 (Gamma Ray American Petroleum Institute Units)
Concentration of Monazite-(La) per GRapi unit = 10.92 (PPM)

Monazite-(La) 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) 332.06 ± 83.01 grams of pure Monazite-(La) .

Estimated Radioactivity from Monazite-(La) - 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 / 7.18 cm 2,166,567 5.86E-05 91,600.36 30.12
100 gm / 3.33 cm 216,657 5.86E-06 9,160.04 3.01
10 gm / 1.55 cm 21,666 5.86E-07 916.00 0.30
1 gm / 7.18 mm 2,167 5.86E-08 91.60 0.03
0.1 gm / 3.33 mm 217 5.86E-09 9.16 0.00
0.01 gm / 1.55 mm 22 5.86E-10 0.92 0.00
0.001 gm / 0.72 mm 2 5.86E-11 0.09 0.00

Weight of pure Monazite-(La) in grams (gm) and Calculated Diameter of a Sphere with a Density of 5.15 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-(La) Classification

Help on  Dana Class: Dana Class: 38.04.03.02 (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
Help on  Strunz Class: 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-(La) Information

Help on References: References: NAME( Sinkankas66) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Mason68)
Help on See Also: See Also: Links to other databases for Monazite-(La) :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - GeoScienceWorld
5 - Google Images
6 - Google Scholar
7 - MinDAT
8 - Mineralienatlas (Deutsch)
9 - Online Mineral Museum
10 - QUT Mineral Atlas
11 - Ruff.Info
12 - Uranium Minerals

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

Monazite-(La)

(La,Ce,Nd)PO4
Dana No: 38.04.03.02 Strunz No: 08.AD.50
Locality:

 

Notes:

 

 
   
 


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