Percleveite-(Ce) Mineral Data

General Percleveite-(Ce) Information

Chemical Formula:

(Ce,La,Nd)2Si2O7

Composition:

Molecular Weight = 442.72 gm

Lanthanum 12.86 % La 15.09 % La₂O₃

Cerium 27.53 % Ce 32.25 % Ce₂O₃

Praeseodymium 2.86 % Pr 3.35 % Pr₂O₃

Samarium 2.38 % Sm 2.76 % Sm₂O₃

Gadolinium 2.13 % Gd 2.46 % Gd₂O₃

Dysprosium 0.37 % Dy 0.42 % Dy₂O₃

Yttrium 2.41 % Y 3.06 % Y₂O₃

Silicon 12.75 % Si 27.28 % SiO₂

Neodymium 11.40 % Nd 13.30 % Nd₂O₃

Oxygen 25.30 % O

______ ______

100.00 % 99.96 % = TOTAL OXIDE

Empirical Formula:

Ce_0.87La_0.41Nd_0.35Y_0.12Pr_0.09Sm_0.07Gd_0.06Dy_0.01Si_2.01O₇

Environment:

Minor grain in cerite-(Ce) ore with magnetite, chalcopyrite and clinoamphibole. Isostructural with Ln2Si2O7.

IMA Status:

Approved IMA 2003 (Dana # Added)

Locality:

Museum sepcimen of cerium-rich ore from the Bastnas deposit, Skinnskatteberg district, Vastmanland, Sweden. Link to MinDat.org Location Data.

Name Origin:

Named for Per Theodor Cleve (1840-1905), discoverer of Holmium (Ho) and Thulium (Tm).

Synonym:

IMA2002-023

Percleveite-(Ce) Crystallography

Axial Ratios:

a:c = 1:3.6409

Cell Dimensions:

a = 6.781, c = 24.689, Z = 8; V = 1,135.25 Den(Calc)= 5.18

Crystal System:

Tetragonal - Pyramidal H-M Symbol (4) Space Group: P 4₁

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

By Intensity(I/I_o): 3.084(1)(008), 3.271(0.31)(202), 3.135(0.27)(203),3.121(0.24)(116), 2.034(0.19)(219), 2.846(0.18)(213), 3.011(0.18),

Physical Properties of Percleveite-(Ce)

Cleavage:

{001} Imperfect

Color:

White, Colorless, Yellowish gray.

Diaphaneity:

Transparent

Habit:

Anhedral Grains - Granular minerals without the expression of crystal shapes

Hardness:

6 - Orthoclase

Luster:

Resinous

Streak:

white

Optical Properties of Percleveite-(Ce)

Gladstone-Dale:

CI calc= -0.012 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1627,KC= 0.1608
Ncalc = 1.83

Optical Data:

Uniaxial (+), w=1.84, e=1.846, bire=0.0060.

Calculated Properties of Percleveite-(Ce)

Electron Density:

Bulk Density (Electron Density)=4.63 gm/cc
note: Specific Gravity of Percleveite-(Ce) =5.18 gm/cc.

Fermion Index:

Fermion Index = 0.05
Boson Index = 0.95

Photoelectric:

PE_{Percleveite-(Ce)}= 324.61 barns/electron
U=PE_{Percleveite-(Ce)} x r_electron=1,502.52 barns/cc.

Radioactivity:

GRapi = 56,880.15 (Gamma Ray American Petroleum Institute Units)
Concentration of Percleveite-(Ce) per GRapi unit = 17.58 (PPM)

Percleveite-(Ce) 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) 534.75 ±133.69 grams of pure Percleveite-(Ce) .

**Estimated Radioactivity from Percleveite-(Ce)** - 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 / 7.17 cm	1,336,754	3.61E-05	56,880.15	18.70
100 gm / 3.33 cm	133,675	3.61E-06	5,688.02	1.87
10 gm / 1.54 cm	13,368	3.61E-07	568.80	0.19
1 gm / 7.17 mm	1,337	3.61E-08	56.88	0.02
0.1 gm / 3.33 mm	134	3.61E-09	5.69	0.00
0.01 gm / 1.54 mm	13	3.61E-10	0.57	0.00
0.001 gm / 0.72 mm	1	3.61E-11	0.06	0.00

Weight of pure Percleveite-(Ce) in grams (gm) and Calculated Diameter of a Sphere with a Density of 5.18 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 ( 2.98 % Th) From Sum REE Elements (59.54 % REE)

Percleveite-(Ce) Classification

Dana Class:

55.02.04.01 (55)Sorosilicate Si2O7 Groups, Generally with No Additional Anions

(55.02)with cations in [6] coordination

(55.02.04)Dana Group

55.02.04.01 Percleveite-(Ce)! (Ce,La,Nd)2Si2O7 P 4₁ 4

Strunz Class:

09.BC.35 09 - SILICATES (Germanates)

09.B - Sorosilicates

09.BC -Si2O7 groups, without non-tetrahedral anions;

09.BC.35 Percleveite-(Ce)! (Ce,La,Nd)2Si2O7 P 4₁ 4

Other Percleveite-(Ce) Information

References:

NAME( AmMin, v 89, p 469) PHYS. PROP.(AmMin, v 89, p 469) OPTIC PROP.(AmMin, v 89, p 469)

See Also:

Links to other databases for Percleveite-(Ce) :
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

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Percleveite-(Ce)

(Ce,La,Nd)2Si2O7
Dana No: 55.02.04.01 Strunz No: 09.BC.35
Locality:

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