Gatelite-(Ce) Mineral Data

General Gatelite-(Ce) Information

Chemical Formula:

(Ca,Ce,La,Nd)4(Al,Mg,Fe)4[Si2O7][SiO4]3(O,F,OH)3

Composition:

Molecular Weight = 1,067.70 gm

Calcium 4.13 % Ca 5.78 % CaO

Lanthanum 6.50 % La 7.63 % La₂O₃

Cerium 18.37 % Ce 21.52 % Ce₂O₃

Praeseodymium 1.32 % Pr 1.54 % Pr₂O₃

Samarium 1.41 % Sm 1.63 % Sm₂O₃

Magnesium 1.14 % Mg 1.89 % MgO

Aluminum 7.83 % Al 14.80 % Al₂O₃

Iron 1.57 % Fe 2.02 % FeO

Silicon 13.42 % Si 28.70 % SiO₂

Hydrogen 0.15 % H 1.35 % H₂O

Neodymium 10.81 % Nd 12.61 % Nd₂O₃

Oxygen 32.82 % O

Fluorine 0.53 % F 0.53 % F

- % F -0.22 % -O=F₂

______ ______

100.00 % 99.78 % = TOTAL OXIDE

Empirical Formula:

Ca_1.1Ce_1.4La_0.5Nd_0.8Pr_0.1Sm_0.1Al_3.1Mg_0.5Fe²⁺_0.3Si_5.1O_20.3(OH)_1.6F_0.3

Environment:

Found as a late-stage mineral in the dolomitic levels of the Trimmouns Talc deposit intergrown with tornebohmite-(Ce). (related to epidote; structure)

IMA Status:

Approved IMA 2003 (Dana # Added)

Locality:

Trimouns talc deposit, Luzenac, Ariege, French Pyrenees, France. Link to MinDat.org Location Data.

Name Origin:

Named for Pierre Gatel, French mineral collector and founder of the Association Francaise de Micromineralogie.

Synonym:

IMA2001-050

Gatelite-(Ce) Image

Images:

Gatelite-(Ce)

Comments: B&W image of crystals of gatelite-(Ce). (AmMin, v88:223).
Location: Trimouns talc deposit, Luzenac, Ariege, French Pyrenees. Scale: Crystal Length 700 µm.
© R. Vernet / American Mineralogist

Gatelite-(Ce) Crystallography

Axial Ratios:

a:b:c =3.1445:1:3.0893

Cell Dimensions:

a = 17.77, b = 5.651, c = 17.458, Z = 4; beta = 116.18° V = 1,573.26 Den(Calc)= 4.51

Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: P 2₁/a

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

By Intensity(I/I_o): 2.967(1)(215), 15.667(0.87)(001), 2.61(0.56)(612), 3.486(0.5)(412), 2.826(0.44)(020), 4.611(0.33)(210), 2.74(0.32)(015), 7.974(0.27)(200), 2.654(0.26)(403),

Crystal Structure:

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Bonazzi P , Bindi L , Parodi G C , American Mineralogist , 88 (2003) p.223-228, Gatelite-(Ce), a new REE-bearing mineral from Trimouns, French Pyrenees:, Crystal structure and polysomatic relationships with epidote and, tornebohmite-(Ce)

Physical Properties of Gatelite-(Ce)

Cleavage:

{100} Good, {001} Imperfect

Color:

Colorless.

Diaphaneity:

Transparent

Fracture:

Brittle - Irregular - Very brittle fracture producing irregular fragments

Habit:

Bladed - Aggregates of thin lath-like crystals (e.g. kyanite).

Habit:

Euhedral Crystals - Occurs as well-formed crystals showing good external form.

Habit:

Striated - Parallel lines on crystal surface or cleavage face.

Hardness:

6-7 - Orthoclase-Quartz

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Gatelite-(Ce)

Optical Data:

Biaxial (?)

NCalc= 1.81 - from Gladstone-Dale relationship (KC = 0.1787) where Ncalc=Dcalc*KC+1

Calculated Properties of Gatelite-(Ce)

Electron Density:

Bulk Density (Electron Density)=4.20 gm/cc
note: Specific Gravity of Gatelite-(Ce) =4.51 gm/cc.

Fermion Index:

Fermion Index = 0.03
Boson Index = 0.97

Photoelectric:

PE_{Gatelite-(Ce)}= 199.82 barns/electron
U=PE_{Gatelite-(Ce)} x r_electron= 838.62 barns/cc.

Radioactivity:

GRapi = 38,208.99 (Gamma Ray American Petroleum Institute Units)
Concentration of Gatelite-(Ce) per GRapi unit = 26.17 (PPM)

Gatelite-(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) 796.06 ±199.02 grams of pure Gatelite-(Ce) .

**Estimated Radioactivity from Gatelite-(Ce)** - weak
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 / 7.51 cm	862,231	2.33E-05	38,208.99	12.56
100 gm / 3.49 cm	86,223	2.33E-06	3,820.90	1.26
10 gm / 1.62 cm	8,622	2.33E-07	382.09	0.13
1 gm / 7.51 mm	862	2.33E-08	38.21	0.01
0.1 gm / 3.49 mm	86	2.33E-09	3.82	0.00
0.01 gm / 1.62 mm	9	2.33E-10	0.38	0.00
0.001 gm / 0.75 mm	1	2.33E-11	0.04	0.00

Weight of pure Gatelite-(Ce) in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.51 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 ( 1.92 % Th) From Sum REE Elements (38.41 % REE)

Gatelite-(Ce) Classification

Dana Class:

58.02.01a.08 (58)Sorosilicate Insular, Mixed, Single, and Larger Tetrahedral Groups

(58.02)with cations in [6] and higher coordination; single and double groups (n=1,2)

(58.02.01a)Epidote group (Clinozoisite subgroup)

58.02.01a.01 Clinozoisite! Ca2Al3(SiO4)3(OH)=Ca2AlAl2(SiO4)(Si2O7)O(OH) P 2₁/m 2/m

58.02.01a.02 Epidote! Ca2(Fe,Al)3(SiO4)3(OH)=Ca2(Fe,Al)Al2(SiO4)(Si2O7)O(OH) P 2₁/m 2/m

58.02.01a.03 Epidote-(Pb)! (Ca,Pb,Sr)2(Al,Fe)3(SiO4)(Si2O7)O(OH) P 2₁/m 2/m

58.02.01a.04 Mukhinite Ca2Al2V(SiO4)3(OH) P 2₁/m 2/m

58.02.01a.05 Piemontite Ca2(Al,Mn,Fe)3(SiO4)3(OH)=Ca2(Mn,Fe)Al2(SiO4)(Si2O7)O(OH) P 2₁/m 2/m

58.02.01a.06 Piemontite-(Sr)! (Ca,Mn)(Sr,Ca)Mn(Al,Mn,Fe)2(SiO4)(Si2O7)O(OH) P 2₁/m 2/m

58.02.01a.07 Manganipiemontite-(Sr)! CaSr(Mn,Fe)2Al[Si3O12](OH) P 2₁/m 2/m

58.02.01a.08 Gatelite-(Ce)! (Ca,Ce,La,Nd)4(Al,Mg,Fe)4[Si2O7][SiO4]3(O,F,OH)3 P 2₁/a 2/m

58.02.01a.09 Clinozoisite-(Sr)! CaSrAl3(Si2O7)(SiO4)O(OH) P 2₁/m 2/m

58.02.01a.10 Uedaite-(Ce)! MnCeAl2Fe(Si2O7)(SiO4)O(OH) P 2₁/m 2/m

58.02.01a.11 Epidote-(Sr)! CaSrAl2Fe(Si2O7)(SiO4)O(OH) P 2₁/m 2/m

Strunz Class:

09.BG.50 09 - SILICATES (Germanates)

09.B - Sorosilicates

09.BG -Sorosilicates with mixed SiO4 and Si2O7 groups;

09.BG.50 Gatelite-(Ce)! (Ca,Ce,La,Nd)4(Al,Mg,Fe)4[Si2O7][SiO4]3(O,F,OH)3 P 2₁/a 2/m

Other Gatelite-(Ce) Information

References:

NAME( AmMin, Vol 88, p 223) PHYS. PROP.(AmMin, Vol 88, p 223)

See Also:

Links to other databases for Gatelite-(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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Print or Cut-and-Paste your Gatelite-(Ce) Specimen Label here :

Gatelite-(Ce)

(Ca,Ce,La,Nd)4(Al,Mg,Fe)4[Si2O7][SiO4]3(O,F,OH)3
Dana No: 58.02.01a.08 Strunz No: 09.BG.50
Locality:

Notes: