Orthochevkinite Mineral Data
General Orthochevkinite Information
Chemical Formula:
(Ce,La,Ca,Na,Th)4(Fe++,Mg)2(Ti,Fe+++)3Si4O22
Composition:
Molecular Weight = 1,170.75 gm
Sodium 0.79 % Na 1.06 % Na2 O
Calcium 2.05 % Ca 2.87 % CaO
Lanthanum 14.24 % La 16.70 % La2 O3
Cerium 14.36 % Ce 16.82 % Ce2 O3
Thorium 7.93 % Th 9.02 % ThO2
Magnesium 1.04 % Mg 1.72 % MgO
Titanium 9.20 % Ti 15.35 % TiO2
Iron 10.73 % Fe 9.21 % FeO / 5.12 % Fe2 O3
Silicon 9.60 % Si 20.53 % SiO2
Oxygen 30.07 % O
______ ______
100.00 % 98.39 % = TOTAL OXIDE
Empirical Formula:
Ce1.2 La1.2 Ca0.6 Na0.4 Th0.4 Fe2+ 1.5 Mg0.5 Ti2.25 Fe3+ 0.75 Si4 O22
Environment:
Alkaline syenite pegmatites. An incompletely characterized material. Physical properties by analogy with chevkinite.
IMA Status:
Not Approved IMA 1920
Locality:
Ifazina-Itorendrika Link to MinDat.org Location Data.
Name Origin:
Named as a possible orthorhombic form of chevkinite.
Orthochevkinite Crystallography
Axial Ratios:
a:b:c =2.3448:1:3.7931
Cell Dimensions:
a = 13.6, b = 5.8, c = 22, Z = 4; V = 1,735.36 Den(Calc)= 4.48
Crystal System:
Orthorhombic Space Group: Unk
X Ray Diffraction:
By Intensity(I/Io ): 4.15(1), 2.7(0.7), 3.78(0.7), 1.69(0.5), 1.49(0.4), 2.53(0.4), 2.88(0.4),
Physical Properties of Orthochevkinite
Cleavage:
None
Color:
Brown.
Habit:
Metamict - Mineral originally crystalline, now amorphous due to radiation damage.
Hardness:
5.5 - Knife Blade
Luster:
Resinous - Greasy
Streak:
black
Optical Properties of Orthochevkinite
Optical Data:
NCalc= 1.95 - from Gladstone-Dale relationship (KC = 0.212) where Ncalc =Dcalc *KC +1
Calculated Properties of Orthochevkinite
Electron Density:
Bulk Density (Electron Density)=4.11 gm/cc note: Specific Gravity of Orthochevkinite =4.48 gm/cc.
Fermion Index:
Fermion Index = 0.01 Boson Index = 0.99
Photoelectric:
PEOrthochevkinite = 326.86 barns/electronU=PEOrthochevkinite x r electron =1,341.82 barns/cc.
Radioactivity:
GRapi = 154,977.55 (Gamma Ray American Petroleum Institute Units)
Concentration of Orthochevkinite per GRapi unit = 6.45 (PPM)
Orthochevkinite 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)
196.26 ± 49.07 grams of pure Orthochevkinite .
Estimated Radioactivity from Orthochevkinite - 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 / 7.53 cm
3,551,676
9.60E-05
154,977.55
50.95
100 gm / 3.49 cm
355,168
9.60E-06
15,497.76
5.10
10 gm / 1.62 cm
35,517
9.60E-07
1,549.78
0.51
1 gm / 7.53 mm
3,552
9.60E-08
154.98
0.05
0.1 gm / 3.49 mm
355
9.60E-09
15.50
0.01
0.01 gm / 1.62 mm
36
9.60E-10
1.55
0.00
0.001 gm / 0.75 mm
4
9.60E-11
0.15
0.00
Weight of pure Orthochevkinite in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.48 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
Orthochevkinite Classification
Dana Class:
56.02.08.04 (56) Sorosilicate Si2O7 Groups and O, OH, F. and H2O
(56.02) with cations in [4] and/or >[4] coordination
(56.02.08) Perierite - Chevkinite group
56.02.08.01 Chevkinite-(Ce) (Ce,La,Ca,Th)4(Fe,Mg)2(Ti,Fe)3Si4O22 C 2/m 2/m
56.02.08.02 Strontiochevkinite (Sr,REE)4Fe(Ti,Zr)2Ti2Si4O22 C 2/a 2/m
56.02.08.03 Perrierite-(Ce) (Ce,La,Ca)4(Fe,Mg)2(Ti,Fe)3Si4O22 C 21/a 2/m
56.02.08.04 Orthochevkinite * (Ce,La,Ca,Na,Th)4(Fe,Mg)2(Ti,Fe)3Si4O22 Unk Ortho
56.02.08.05 Rengeite ! Sr4ZrTi4Si4O22 P 21 /a 2/m
56.02.08.06 Matsubaraite ! Sr4TiTi4Si4O22 P 21 /a 2/m
56.02.08.07 Polyakovite-(Ce) ! (Ce,La,Nd,Pr,Ca)4(Mg,Fe)(Cr,Fe)2(Ti,Nb)2Si4O22 C 2/m 2/m
56.02.08.08 Maoniupingite-(Ce) ! (REE,Ca)4(Fe,Ti,Fe,[])(Ti,Fe,Fe,Nb)4Si4O22 C 2/m 2/m
56.02.08.09 Dingdaohengite-(Ce) ! (Ce,La)4Fe(Ti,Fe,Mg,Fe)2Ti2Si4O22 P 21 /a (pseudo-C 2/m) 2/m
Strunz Class:
09.BE.07.0 09 - SILICATES (Germanates)
09.B - Sorosilicates
09.BE -Si2O7 groups with additional anions;
09.BE.07.0 Orthochevkinite * (Ce,La,Ca,Na,Th)4(Fe,Mg)2(Ti,Fe)3Si4O22 Unk Ortho
Other Orthochevkinite Information
References:
NAME( Dana8) PHYS. PROP.(Dana8)
See Also:
Links to other databases for Orthochevkinite :
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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Orthochevkinite
(Ce,La,Ca,Na,Th)4(Fe++,Mg)2(Ti,Fe+++)3Si4O22
Dana No: 56.02.08.04 Strunz No: 09.BE.07.0
Locality:
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