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 % La2 O3
Cerium 18.37 % Ce 21.52 % Ce2 O3
Praeseodymium 1.32 % Pr 1.54 % Pr2 O3
Samarium 1.41 % Sm 1.63 % Sm2 O3
Magnesium 1.14 % Mg 1.89 % MgO
Aluminum 7.83 % Al 14.80 % Al2 O3
Iron 1.57 % Fe 2.02 % FeO
Silicon 13.42 % Si 28.70 % SiO2
Hydrogen 0.15 % H 1.35 % H2 O
Neodymium 10.81 % Nd 12.61 % Nd2 O3
Oxygen 32.82 % O
Fluorine 0.53 % F 0.53 % F
- %
F -0.22 % -O=F2
______ ______
100.00 % 99.78 % = TOTAL OXIDE
Empirical Formula:
Ca1.1 Ce1.4 La0.5 Nd0.8 Pr0.1 Sm0.1 Al3.1 Mg0.5 Fe2+ 0.3 Si5.1 O20.3 (OH)1.6 F0.3
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) 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 - Prismatic H-M Symbol (2/m) Space Group: P 21 /a
X Ray Diffraction:
By Intensity(I/Io ): 2.967(1)(2 15), 15.667(0.87)(001), 2.61(0.56)(6 12),
3.486(0.5)(4 12), 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),
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:
PEGatelite-(Ce) = 199.82 barns/electronU=PEGatelite-(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 Bequerols (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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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
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