Mottanaite-(Ce) Mineral Data

General Mottanaite-(Ce) Information

Chemical Formula:

Ca4(Ce,Ca)2AlBe2[Si4B4O22]O2

Composition:

Molecular Weight = 1,007.13 gm

Calcium 18.31 % Ca 25.61 % CaO

Cerium 20.87 % Ce 24.44 % Ce₂O₃

Thorium 2.30 % Th 2.62 % ThO₂

Titanium 0.48 % Ti 0.79 % TiO₂

Beryllium 0.72 % Be 1.99 % BeO

Aluminum 1.34 % Al 2.53 % Al₂O₃

Iron 2.22 % Fe 3.17 % Fe₂O₃

Silicon 11.15 % Si 23.86 % SiO₂

Boron 4.29 % B 13.83 % B₂O₃

Hydrogen 0.05 % H 0.45 % H₂O

Oxygen 37.33 % O

Fluorine 0.94 % F 0.94 % F

- % F -0.40 % -O=F₂

______ ______

100.00 % 99.84 % = TOTAL OXIDE

Empirical Formula:

Ca₄Ce_1.5Th_0.1Ca_0.6Al_0.5Fe³⁺_0.4Ti_0.1Be_0.8(Si4B4O22)O(OH)_0.5F_0.5

Environment:

Miarolitic cavities in alkali-syenitic ejecta enclosed in pyroclastic formations of the Roma Comagmatic Province. (hellandite group; structure)

IMA Status:

Approved IMA 2001 (Dana # Added)

Locality:

Sabatini volcanic complex, Latium, Italy. Link to MinDat.org Location Data.

Name Origin:

Named for Annibale Mottana, Professor of Mineralogy at the University of Roma Tre (Italy).

Synonym:

IMA2001-020

Mottanaite-(Ce) Image

Images:

Mottanaite-(Ce)

Comments: Brown crystals of mottanaite-(Ce) in matrix.
Location: Monte Cavallucio, Sacrofano, Campagnano, Latium (Lazio), Italy. Scale: Picture size 5 mm.
© Thomas Witzke / Abraxas-Verlag

Mottanaite-(Ce) Crystallography

Axial Ratios:

a:b:c =4.0101:1:2.1592

Cell Dimensions:

a = 19.032, b = 4.746, c = 10.248, Z = 2; beta = 110.97° V = 864.35 Den(Calc)= 3.87

Crystal System:

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

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

By Intensity(I/I_o): 2.854(1)(411), 2.646(0.86)(413), 2.916(0.86)(212), 3.085(0.85)(412), 2.635(0.84)(611), 2.647(0.84)(013), 3.243(0.8)(410), 3.452(0.67)(2

Physical Properties of Mottanaite-(Ce)

Cleavage:

None

Color:

Pale brown.

Density:

3.61

Diaphaneity:

Transparent

Fracture:

Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.

Habit:

Anhedral Grains - Granular minerals without the expression of crystal shapes

Habit:

Tabular - Form dimensions are thin in one direction.

Luster:

Vitreous (Glassy)

Optical Properties of Mottanaite-(Ce)

Gladstone-Dale:

CI meas= 0.028 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.093 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1793,KPDmeas= 0.1922,KC= 0.1978
Ncalc = 1.71 - 1.77

Optical Data:

Biaxial (-), a=1.68, b=1.694, g=1.708, bire=0.0280

Calculated Properties of Mottanaite-(Ce)

Electron Density:

Bulk Density (Electron Density)=3.44 gm/cc
note: Specific Gravity of Mottanaite-(Ce) =3.61 gm/cc.

Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Photoelectric:

PE_{Mottanaite-(Ce)}= 155.80 barns/electron
U=PE_{Mottanaite-(Ce)} x r_electron= 535.32 barns/cc.

Radioactivity:

GRapi = 46,782.29 (Gamma Ray American Petroleum Institute Units)
Concentration of Mottanaite-(Ce) per GRapi unit = 21.38 (PPM)

Mottanaite-(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) 650.17 ±162.54 grams of pure Mottanaite-(Ce) .

**Estimated Radioactivity from Mottanaite-(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 / 8.09 cm	1,032,168	2.79E-05	46,782.29	15.38
100 gm / 3.75 cm	103,217	2.79E-06	4,678.23	1.54
10 gm / 1.74 cm	10,322	2.79E-07	467.82	0.15
1 gm / 8.09 mm	1,032	2.79E-08	46.78	0.02
0.1 gm / 3.75 mm	103	2.79E-09	4.68	0.00
0.01 gm / 1.74 mm	10	2.79E-10	0.47	0.00
0.001 gm / 0.81 mm	1	2.79E-11	0.05	0.00

Weight of pure Mottanaite-(Ce) in grams (gm) and Calculated Diameter of a Sphere with a Density of 3.61 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

Mottanaite-(Ce) Classification

Dana Class:

54.02.02.05 (54)Nesosilicate Borosilicates and Some Beryllosilicates

(54.02)with B in [4] coordination

(54.02.02)Hellandite group

54.02.02.01 Hellandite-(Y) (Ca,REE)4(Y,Ce)2(Al,[])2[Si4B4O22](OH)2 P 2/a 2/m

54.02.02.02 Tadzhikite-(Y)! Ca4(Y,Ce)2(Ti,Al,Fe,[])2[Si4B4O22](OH)2 P 2/a 2/m

54.02.02.03 Tadzhikite-(Ce) Ca4(Ce,Y)2(Ti,Al,Fe,[])2[Si4B4O22](OH)2 P 2/a 2/m

54.02.02.04 Hellandite-(Ce)! (Ca3REE)4Ce2Al[]2[Si4B4O22](OH)2 P 2/a 2/m

54.02.02.05 Mottanaite-(Ce)! Ca4(Ce,Ca)2AlBe2[Si4B4O22]O2 P 2/a 2/m

54.02.02.06 Ciprianiite! Ca4[(Th,U)(REE)]2(Al,[])2[Si4B4O22](OH,F)2 P 2/a 2/m

54.02.02.07 Piergorite-(Ce)! Ca8Ce2(Al0.5Fe0.5)([],Li,Be)2Si6B8O36(OH,F)2 P 2/a 2/m

Strunz Class:

09.DK.20 09 - SILICATES (Germanates)

09.D - Inosilicates* Structural terminology according to Liebau (1985)

09.DK -Inosilicates with 5-periodic single chains

09.DK.20 Hellandite-(Y) (Ca,REE)4(Y,Ce)2(Al,[])2[Si4B4O22](OH)2 P 2/a 2/m

09.DK.20 Tadzhikite-(Ce) Ca4(Ce,Y)2(Ti,Al,Fe,[])2[Si4B4O22](OH)2 P 2/a 2/m

09.DK.20 Tadzhikite-(Y)! Ca4(Y,Ce)2(Ti,Al,Fe,[])2[Si4B4O22](OH)2 P 2/a 2/m

09.DK.20 Ciprianiite! Ca4[(Th,U)(REE)]2(Al,[])2[Si4B4O22](OH,F)2 P 2/a 2/m

09.DK.20 Hellandite-(Ce)! (Ca3REE)4Ce2Al[]2[Si4B4O22](OH)2 P 2/a 2/m

09.DK.20 Mottanaite-(Ce)! Ca4(Ce,Ca)2AlBe2[Si4B4O22]O2 P 2/a 2/m

Other Mottanaite-(Ce) Information

References:

NAME( AmMin, Vol 87, p 739) PHYS. PROP.(AmMin, Vol 87, p 739) OPTIC PROP.(AmMin, Vol 87, p 739)

See Also:

Links to other databases for Mottanaite-(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 Mottanaite-(Ce) Specimen Label here :

Mottanaite-(Ce)

Ca4(Ce,Ca)2AlBe2[Si4B4O22]O2
Dana No: 54.02.02.05 Strunz No: 09.DK.20
Locality:

Notes: