Röntgenite-(Ce)
A valid IMA mineral species - grandfathered
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About Röntgenite-(Ce)
Wilhelm Conrad Röntgen
Formula:
Ca2(Ce,La)3(CO3)5F3
Colour:
Yellow to brown, green
Lustre:
Waxy
Hardness:
4½
Specific Gravity:
4.19 (Calculated)
Crystal System:
Trigonal
Name:
Named in honor of Wilhelm Conrad Röntgen (27 March 1845, Lennep, German Confederation - 10 February 1923, Munich, Bavaria, Weimar Republic), physicist who discovered X-rays, because X-rays alone were used to prove the existence of the species. For his discovery of X-rays, Röntgen was awarded the 1901 Nobel Prize in Physics. The radioactive element roentgenium and a minor planet are also named in his honor. The species was originally named simply röntgenite (and appears in print as roentgenite); the suffix was added in 1987 by the IMA to denote the dominant REE.
Name Encoding
ASCII-7:
Rontgenite-(Ce)
Unique Identifiers
Mindat ID:
3429
Long-form identifier:
mindat:1:1:3429:2
IMA Classification of Röntgenite-(Ce)
Approved, 'Grandfathered' (first described prior to 1959)
IMA status notes:
Renamed by the IMA
IMA Formula:
Ca2Ce3+3(CO3)5F3
Approval year:
1987
First published:
1953
Classification of Röntgenite-(Ce)
5.BD.20d
5 : CARBONATES (NITRATES)
B : Carbonates with additional anions, without H2O
D : With rare earth elements (REE)
5 : CARBONATES (NITRATES)
B : Carbonates with additional anions, without H2O
D : With rare earth elements (REE)
16a.1.6.1
16a : ANHYDROUS CARBONATES CONTAINING HYDROXYL OR HALOGEN
1 : (AB)(XO3)Zq
16a : ANHYDROUS CARBONATES CONTAINING HYDROXYL OR HALOGEN
1 : (AB)(XO3)Zq
12.1.16
12 : Carbonates with other anions
1 : Carbonates with halides
12 : Carbonates with other anions
1 : Carbonates with halides
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Rng-Ce | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Röntgenite-(Ce)
Waxy
Transparency:
Transparent, Translucent
Colour:
Yellow to brown, green
Hardness:
4½ on Mohs scale
Fracture:
Sub-Conchoidal
Density:
4.19 g/cm3 (Calculated)
Optical Data of Röntgenite-(Ce)
Type:
Uniaxial (+)
RI values:
nω = 1.658 - 1.662 nε = 1.756
Max. Birefringence:
δ = 0.094 - 0.098
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Very High (positive)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized uniaxial interference figure - the conoscopic
(convergent-light, Bertrand-lens-in) view, for a grain cut with the optic axis
centred and vertical. The coloured rings are isochromatics, computed with the
same physics as the Michel-Lévy bar above; the dark cross is the isogyre.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
For a genuinely uniaxial mineral viewed this way, that cross stays perfectly stationary if you rotate the stage - unlike a biaxial mineral, where it splits apart on rotation. That invariance is itself the standard diagnostic test for telling uniaxial and biaxial minerals apart at the microscope.
Chemistry of Röntgenite-(Ce)
Mindat Formula:
Ca2(Ce,La)3(CO3)5F3
Element Weights:
Crystallography of Röntgenite-(Ce)
Crystal System:
Trigonal
Class (H-M):
3 - Pyramidal
Space Group:
R3
Cell Parameters:
a = 7.13(3) Å, c = 69.4(2) Å
Ratio:
a:c = 1 : 9.734
Unit Cell V:
3,055.41 ų (Calculated from Unit Cell)
Z:
9
Morphology:
Hexagonal
Twinning:
On (0001), rare.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 23.13 Å | (100) |
| 11.57 Å | (70) |
| 7.71 Å | (13) |
| 4.627 Å | (44) |
| 3.565 Å | (49) |
| 2.824 Å | (48) |
| 2.058 Å | (15) |
| 1.941 Å | (16) |
| 1.881 Å | (18) |
Comments:
ICDD-PDF 35-579
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Near-surface Processes | |
| 22 : Hydration and low-? subsurface aqueous alteration (see also #23) | |
| Stage 4b: Highly evolved igneous rocks | >3.0 |
| 35 : Ultra-alkali and agpaitic igneous rocks |
Geological Setting:
Pegmatites
Type Occurrence of Röntgenite-(Ce)
General Appearance of Type Material:
Intimately intergrown with synchisite, parisite, and bastnaesite, simulating single crystals.
Place of Conservation of Type Material:
Harvard University, Cambridge, Massachusetts, USA, 84233.
National Museum of Natural History, Washington, D.C., USA, R2609, R2613, R2615.
National Museum of Natural History, Washington, D.C., USA, R2609, R2613, R2615.
Geological Setting of Type Material:
A late-stage hydrothermal mineral in granite pegmatite.
Associated Minerals at Type Locality:
Synonyms of Röntgenite-(Ce)
Other Language Names for Röntgenite-(Ce)
Dutch:Röntgeniet-(Ce)
German:Röntgenit-(Ce)
Common Associates
Associations Based on Photo Data:
| 2 photos of Röntgenite-(Ce) associated with Parisite-(Ce) | CaCe2(CO3)3F2 |
| 2 photos of Röntgenite-(Ce) associated with Synchysite-(Ce) | CaCe(CO3)2F |
| 2 photos of Röntgenite-(Ce) associated with Huanghoite-(Ce) | BaCe(CO3)2F |
| 2 photos of Röntgenite-(Ce) associated with Aegirine | NaFe3+Si2O6 |
| 1 photo of Röntgenite-(Ce) associated with Fluorapatite | Ca5(PO4)3F |
| 1 photo of Röntgenite-(Ce) associated with 'Emerald' | Be3Al2(Si6O18) |
| 1 photo of Röntgenite-(Ce) associated with Franconite | Na(Nb2O5)(OH) · 3H2O |
| 1 photo of Röntgenite-(Ce) associated with Ferriallanite-(Ce) | (CaCe)(Fe3+AlFe2+)O[Si2O7][SiO4](OH) |
| 1 photo of Röntgenite-(Ce) associated with Fluorite | CaF2 |
| 1 photo of Röntgenite-(Ce) associated with Thorbastnäsite | ThCa(CO3)2F2 · 3H2O |
Related Minerals - Strunz-mindat Grouping
| 5.BD. | Cordylite-(La) | (Na,Ca)Ba(La,Ce,Sr)2(CO3)4F |
| 5.BD.05 | Cordylite-(Ce) | NaBaCe2(CO3)4F |
| 5.BD.05 | 'Unnamed (Cordylite-like Calcium-Barium-Cerium Carbonate-Fluoride)' | Ca◻Ba2Ce4[CO3]8F2 |
| 5.BD.05 | Lukechangite-(Ce) | Na3Ce2(CO3)4F |
| 5.BD.10 | 'Zhonghuacerite-(Ce)' | Ba2Ce(CO3)3F |
| 5.BD.10 | Kukharenkoite-(Ce) | Ba2Ce(CO3)3F |
| 5.BD.10 | Kukharenkoite-(La) | Ba2(La,Ce,Th)(CO3)3F |
| 5.BD.15 | Cebaite-(Ce) | Ba3Ce2(CO3)5F2 |
| 5.BD.15 | 'Cebaite-(Nd)' | Ba3(Nd,Ce)2(CO3)5F2 |
| 5.BD.18 | Arisite-(Ce) | NaCe2(CO3)2[F2x(CO3)1-x]F |
| 5.BD.18 | Arisite-(La) | NaLa2(CO3)2[F2x(CO3)1-x]F |
| 5.BD.20c | Synchysite-(Ce) | CaCe(CO3)2F |
| 5.BD.20c | Synchysite-(Nd) | CaNd(CO3)2F |
| 5.BD.20c | Synchysite-(Y) | CaY(CO3)2F |
| 5.BD.20a | Bastnäsite-(Ce) | Ce(CO3)F |
| 5.BD.20b | Parisite-(Ce) | CaCe2(CO3)3F2 |
| 5.BD.20a | Bastnäsite-(La) | La(CO3)F |
| 5.BD.20b | Parisite-(Nd) | Ca(Nd,Ce,La)2(CO3)3F2 |
| 5.BD.20a | Bastnäsite-(Y) | Y(CO3)F |
| 5.BD.20b | Parisite-(La) | CaLa2(CO3)3F2 |
| 5.BD.20a | Thorbastnäsite | ThCa(CO3)2F2 · 3H2O |
| 5.BD.20a | Hydroxylbastnäsite-(Ce) | Ce(CO3)(OH) |
| 5.BD.20a | Hydroxylbastnäsite-(Nd) | Nd(CO3)(OH) |
| 5.BD.20c | 'Hydroxylsynchysite-(Ce)' | Ca(Ce,La)(CO3)2(OH) |
| 5.BD.20c | 'Synchysite-(La)' | Ca(La,Nd)(CO3)2F |
| 5.BD.20a | Bastnäsite-(Nd) | Nd(CO3)F |
| 5.BD.20a | Hydroxylbastnäsite-(La) | (La,Nd,Ce)(CO3)(OH,F) |
| 5.BD.25 | Qaqarssukite-(Ce) | Ba(Ce,REE)(CO3)2F |
| 5.BD.25 | Horváthite-(Y) | NaY(CO3)F2 |
| 5.BD.35 | Huanghoite-(Ce) | BaCe(CO3)2F |
| 5.BD.35 | Huanghoite-(Nd) | BaNd(CO3)2F |
| 5.BD.45 | Bayanoboite-(Y) | Ba2Y(CO3)2F3 |
Other Information
Notes:
Dissolves in strong acids (ex. 6N HNO3). In solubility, roentgenite is intermediate between synchisite and parisite.
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Röntgenite-(Ce)
mindat.org URL:
https://www.mindat.org/min-3429.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
Mineral Dealers:
References for Röntgenite-(Ce)
Reference List:
Donnay, Gabrielle (1953) Roentgenite, 3CeFCO3· 2CaCO3, a new mineral from Greenland. American Mineralogist, 38 (9-10) 868-871
Donnay, Gabrielle, Donnay, J. D. H. (1953) The crystallography of bastnaesite, parisite, roentgenite and synchisite. American Mineralogist, 38 (11-12) 932-963
Nickel, Ernest H., Mandarino, Joseph A. (1987) Procedures involving the IMA Commission on New Minerals and Mineral Names and guidelines on mineral nomenclature. American Mineralogist, 72 (9-10) 1031-1042
Localities for Röntgenite-(Ce)
Showing 24 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
Australia | |
| Spandler et al. (2016) +1 other reference |
Canada | |
| McLaughlin (1990) |
| Horváth et al. (2000) +1 other reference |
China | |
| Pavel M. Kartashov (n.d.) |
| Anthony |
Colombia | |
| Zeug et al. (2021) |
France | |
| Perinet (2014) |
| analysed at CNRS Nantes |
| Pierre le Roc'h collection (analyzed by Yves Lulzac, BRGM Nantes, end May 2009) |
Germany | |
| Wand et al. (1989) +3 other references |
Greenland (TL) | |
| Donnay (1953) |
Mongolia | |
| Kynický et al. (2005) +1 other reference |
| Pavel M. Kartashov analytical data (2012) |
Namibia | |
| Lohmeier et al. (2023) |
Romania | |
| Szakáll et al. (2010) |
Russia | |
| Kasatkin et al. (2019) |
| Konyshev et al. (2026) |
| Pavel M. Kartashov (n.d.) |
Slovakia | |
| Ondrejka et al. (2007) |
South Korea | |
| Pavel M. Kartashov (n.d.) |
USA | |
| Watts et al. (2026) |
| Gleba (2008) |
| Caruso +1 other reference |
| csmres.jmu.edu (n.d.) |
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Poudrette quarry, Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Québec, Canada