Rontgenite-(Ce) Mineral Data

General Rontgenite-(Ce) Information

Chemical Formula:

Ca2(Ce,La)3(CO3)5F3

Composition:

Molecular Weight = 856.64 gm

Calcium 9.36 % Ca 13.09 % CaO

Lanthanum 12.16 % La 14.26 % La₂O₃

Cerium 36.80 % Ce 43.11 % Ce₂O₃

Carbon 7.01 % C 25.69 % CO₂

Oxygen 28.02 % O

Fluorine 6.65 % F 6.65 % F

- % F -2.80 % -O=F₂

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ca₂Ce_2.25La_0.75(CO₃)₅F₃

IMA Status:

Valid Species (Pre-IMA) 1953

Locality:

Narssarssuk, Greenland. Link to MinDat.org Location Data.

Name Origin:

Named for William Conrad von Rontgen (1845-1923), German physicist and discoverer of X-rays.

Name Pronunciation:

Rontgenite-(Ce) + Pronunciation

Rontgenite-(Ce) Image

Images:

Rontgenite-(Ce)

Comments: Gemmy and lustrous rontgenite-(Ce) crystals to 1.5 mm on an albite matrix.
Location: Narsarsuk, Igaliko, Greenland. Scale: 3.7 x 1.5 cm.
© John Veevaert

Images:

Thorbastnasite Rontgenite-(Ce)

Comments: Tny white, acicular thorbastnasite crystals to less than 1 mm in sprays. The thorbastnasite forms the cores the 'needles', with white epitaxial rontgenite-(Ce) coating.
Location: Mont Saint-Hilaire, Quebec, Canada. Scale: Needle Size < 1 mm.
© William Lechner / Dakota Matrix

Rontgenite-(Ce) Crystallography

Axial Ratios:

a:c = 1:9.73352

Cell Dimensions:

a = 7.13, c = 69.4, Z = 9; V = 3,055.41 Den(Calc)= 4.19

Crystal System:

Trigonal - Pyramidal H-M Symbol (3) Space Group: R 3

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

By Intensity(I/I_o): 23.133(1), 11.567(0.7), 3.565(0.49),

Physical Properties of Rontgenite-(Ce)

Color:

Yellow, Brown.

Diaphaneity:

Transparent to Translucent

Hardness:

4.5 - Between Fluorite and Apatite

Optical Properties of Rontgenite-(Ce)

Gladstone-Dale:

CI calc= -0.007 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1692,KC= 0.168
Ncalc = 1.7

Optical Data:

Uniaxial (+), w=1.662, e=1.756, bire=0.0940.

Calculated Properties of Rontgenite-(Ce)

Electron Density:

Bulk Density (Electron Density)=3.82 gm/cc
note: Specific Gravity of Rontgenite-(Ce) =4.19 gm/cc.

Fermion Index:

Fermion Index = 0.0011414107
Boson Index = 0.9988585893

Photoelectric:

PE_{Rontgenite-(Ce)}= 245.25 barns/electron
U=PE_{Rontgenite-(Ce)} x r_electron= 936.26 barns/cc.

Radioactivity:

GRapi = 47,585.83 (Gamma Ray American Petroleum Institute Units)
Concentration of Rontgenite-(Ce) per GRapi unit = 21.01 (PPM)

Rontgenite-(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) 639.20 ±159.80 grams of pure Rontgenite-(Ce) .

**Estimated Radioactivity from Rontgenite-(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 / 7.70 cm	1,096,781	2.96E-05	47,585.83	15.64
100 gm / 3.57 cm	109,678	2.96E-06	4,758.58	1.56
10 gm / 1.66 cm	10,968	2.96E-07	475.86	0.16
1 gm / 7.70 mm	1,097	2.96E-08	47.59	0.02
0.1 gm / 3.57 mm	110	2.96E-09	4.76	0.00
0.01 gm / 1.66 mm	11	2.96E-10	0.48	0.00
0.001 gm / 0.77 mm	1	2.96E-11	0.05	0.00

Weight of pure Rontgenite-(Ce) in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.19 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 ( 2.45 % Th) From Sum REE Elements (48.96 % REE)

Rontgenite-(Ce) Classification

Dana Class:

16a.01.06.01 (16a)Carbonates - Hydroxyl or Halogen

(16a.01)in the Bastnasite/Shynchysite/Parasite Groups

(16a.01.06)Dana Group

16a.01.06.01 Rontgenite-(Ce) Ca2(Ce,La)3(CO3)5F3 R 3 3

Strunz Class:

05.BD.20d 05 - CARBONATES (NITRATES)

05.B - Carbonates with additional anions, without H2O

05.BD -With rare-earth elements (REE)

05.BD.20d Rontgenite-(Ce) Ca2(Ce,La)3(CO3)5F3 R 3 3

Other Rontgenite-(Ce) Information

References:

NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Rontgenite-(Ce) :
1 - Alkali-Nuts(English)
2 - Alkali-Nuts(Francais)
3 - Am. Min. Crystal Structure Database
4 - Athena
5 - EUROmin Project
6 - GeoScienceWorld
7 - Google Images
8 - Google Scholar
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info

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Print or Cut-and-Paste your Rontgenite-(Ce) Specimen Label here :

Rontgenite-(Ce)

Ca2(Ce,La)3(CO3)5F3
Dana No: 16a.01.06.01 Strunz No: 05.BD.20d
Locality:

Notes:

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