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Mottanaite-(Ce)

A valid IMA mineral species
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About Mottanaite-(Ce)Hide

04798880017271929621677.jpg
Annibale Mottana
Formula:
Ca4(Ce,REE)Σ2Al(Be1.5◻0.5)Σ2[B4Si4O22]O2
Formerly Ca4(CeCa)AlBe2(Si4B4O22)O2; changed due to approval of the IMA 18-D proposal
Colour:
Brown
Lustre:
Vitreous
Specific Gravity:
3.61
Crystal System:
Monoclinic
Name:
Named in 2002 by Giancarlo Della Ventura, Paola Bonazzi, Roberta Oberti, and Luisa Ottolini in honour of Annibale Mottana (b. 1940), Professor of Mineralogy, University of Roma Tre, "in recognition of his leadership and support of investigations and cataloguing of the Latium minerals, during which the mottanaite-(Ce) sample was found". The suffix denotes the cerium content.
This page provides mineralogical data about Mottanaite-(Ce).


Unique IdentifiersHide

Mindat ID:
10798
Long-form identifier:
mindat:1:1:10798:3

Similar NamesHide

MutinaiteA valid IMA mineral speciesNa3Ca4Si85Al11O192 · 60H2O

IMA Classification of Mottanaite-(Ce)Hide

Approved
IMA Formula:
Ca4Ce3+2Al(Be1.5◻0.5)[B4Si4O22]O2
Approval year:
2001
First published:
2002
Approval history:
2018: Formula changed (IMA 18-D)

Classification of Mottanaite-(Ce)Hide

9.DK.20

9 : SILICATES (Germanates)
D : Inosilicates
K : Inosilicates with 5-periodic single chains

Mineral SymbolsHide

As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.

SymbolSourceReference for Standard
Mot-CeIMA–CNMNCWarr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43

Physical Properties of Mottanaite-(Ce)Hide

Vitreous
Transparency:
Transparent, Translucent
Colour:
Brown
Streak:
White
Tenacity:
Brittle
Cleavage:
None Observed
None
Fracture:
Conchoidal
Density:
3.61(4) g/cm3 (Measured)    3.88 g/cm3 (Calculated)

Optical Data of Mottanaite-(Ce)Hide

Type:
Biaxial (-)
RI values:
nα = 1.68 nβ = 1.694 nγ = 1.708
2V:
Measured: ~90°
Max. Birefringence:
δ = 0.028
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.

Surface Relief:
Very High (positive)
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 biaxial acute bisectrix (Bxa) interference figure - the conoscopic view for a grain cut perpendicular to the acute bisectrix, using this mineral's 2V. The two small white dots mark the melatopes - the points where the two optic axes emerge - and are shown only when they fall within the field of view. The coloured bands are isochromatics, and the dark bands are isogyres.

Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.

No measured or calculated 2V is on file for this mineral, so the value used here (89°) is estimated from its recorded refractive indices and optic sign, not from a direct 2V measurement.
Dispersion:
r > v, strong.

Chemistry of Mottanaite-(Ce)Hide

Mindat Formula:
Ca4(Ce,REE)Σ2Al(Be1.5◻0.5)Σ2[B4Si4O22]O2

Formerly Ca4(CeCa)AlBe2(Si4B4O22)O2; changed due to approval of the IMA 18-D proposal

Crystallography of Mottanaite-(Ce)Hide

Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
P2/b
Setting:
P2/a
Cell Parameters:
a = 19.032(9) Å, b = 4.746(4) Å, c = 10.248(5) Å
β = 110.97(5)°
Ratio:
a:b:c = 4.01 : 1 : 2.159
Unit Cell V:
864.3 ų
Z:
2
Morphology:
Tabular on {010}.

Crystal StructureHide

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IDSpeciesReferenceLinkYearLocalityPressure (GPa)Temp (K)
0002818Mottanaite-(Ce)Della Ventura G, Bonazzi P, Oberti R, Ottolini L (2002) Ciprianiite and mottanaite-(Ce), two new minerals of the hellandite group from Latium (Italy) American Mineralogist 87 739-74420020293
CIF Raw Data - click here to close

X-Ray Powder DiffractionHide

Powder Diffraction Data:
d-spacingIntensity
2.854 Å(100)
2.916 Å(86)
2.646 Å(86)
3.085 Å(85)
2.647 Å(84)
2.635 Å(84)
3.243 Å(80)

Geological EnvironmentHide

Paragenetic Mode(s):
Paragenetic ModeEarliest Age (Ga)
Stage 4b: Highly evolved igneous rocks>3.0
35 : Ultra-alkali and agpaitic igneous rocks

Type Occurrence of Mottanaite-(Ce)Hide

General Appearance of Type Material:
Small (<0.5 mm), brown, tabular crystals.
Place of Conservation of Type Material:
Mineralogy Museum, University of Rome, Italy, 30023/1.
Geological Setting of Type Material:
In miarolitic cavities in alkali-syenitic ejecta enclosed in pyroclastic formations.
Associated Minerals at Type Locality:

Synonyms of Mottanaite-(Ce)Hide

Other Language Names for Mottanaite-(Ce)Hide

Relationship of Mottanaite-(Ce) to other SpeciesHide

Other Members of Hellandite Group:
CiprianiiteCa4[(Th,U),Ca]Σ2Al(Be0.5◻1.5)Σ2[B4Si4O22](OH)2Mon. 2/m : P2/b
Ferri-hellandite-(Ce)(Ca3Ce)Ce2Fe3+◻2B4Si4O22(OH)2Mon. 2/m : P2/b
Ferri-mottanaite-(Ce)Ca4Ce2Fe3+(Be1.5◻0.5)[Si4B4O22]O2Mon. 2/m : P2/b
Hellandite-(Ce)(Ca,REE)4Ce2Al◻2(B4Si4O22) (OH)2Mon. 2/m : P2/b
Hellandite-(Y)(Ca,REE)4Y2Al◻2(B4Si4O22) (OH)2Mon. 2/m : P2/b
Tadzhikite-(Ce)Ca4Ce3+2Ti◻2(B4Si4O22)(OH)2Mon. 2/m : P2/b

Common AssociatesHide

Associations Based on Photo Data:
1 photo of Mottanaite-(Ce) associated with Feldspar Group

Related Minerals - Strunz-mindat GroupingHide

9.DK.FerrorhodoniteCaMn3Fe[Si5O15]Tric. 1 : P1
9.DK.VittinkiiteMnMn3Mn[Si5O15]Tric. 1 : P1
9.DK.Ferri-hellandite-(Ce)(Ca3Ce)Ce2Fe3+◻2B4Si4O22(OH)2Mon. 2/m : P2/b
9.DK.ShijiangshanitePb3CaAl(Si5O14)(OH)3 · 3H2OTrig. 3m : R3c
9.DK.05NambuliteLiMn2+4Si5O14(OH)Tric.
9.DK.05MarsturiteNaCaMn3Si5O14(OH)Tric. 1 : P1
9.DK.05Natronambulite(Na,Li)(Mn,Ca)4Si5O14OHTric.
9.DK.05RhodoniteCaMn3Mn[Si5O15]Tric. 1
9.DK.05Scandiobabingtonite(Ca,Na)2(Fe2+,Mn)(Sc,Fe3+)Si5O14(OH)Tric.
9.DK.05LithiomarsturiteLiCaMn3Si5O14(OH)Tric. 1 : P1
9.DK.05ManganbabingtoniteCa2Mn2+Fe3+Si5O14(OH)Tric. 1 : P1
9.DK.05Fowlerite(Mn2+,Zn,Ca)SiO3
9.DK.05BabingtoniteCa2Fe2+Fe3+Si5O14(OH)Tric. 1 : P1
9.DK.10SantaclaraiteCaMn4[Si5O14OH](OH) · H2OTric. 1 : P1
9.DK.15SaneroiteNaMn2+5[Si5O14(OH)](VO3)(OH)Tric. 1 : P1
9.DK.20Ferri-mottanaite-(Ce)Ca4Ce2Fe3+(Be1.5◻0.5)[Si4B4O22]O2Mon. 2/m : P2/b
9.DK.20Tadzhikite-(Ce)Ca4Ce3+2Ti◻2(B4Si4O22)(OH)2Mon. 2/m : P2/b
9.DK.20'Hellandite-(Yb)'(Ca,Y)4(Yb,Y)2(Al,Fe3+,Ti4+)(Be,Li)2[B4Si4O22](O,F,OH)2
9.DK.20CiprianiiteCa4[(Th,U),Ca]Σ2Al(Be0.5◻1.5)Σ2[B4Si4O22](OH)2Mon. 2/m : P2/b
9.DK.20Hellandite-(Y)(Ca,REE)4Y2Al◻2(B4Si4O22) (OH)2Mon. 2/m : P2/b
9.DK.20Hellandite-(Ce)(Ca,REE)4Ce2Al◻2(B4Si4O22) (OH)2Mon. 2/m : P2/b

Fluorescence of Mottanaite-(Ce)Hide

Not fluorescent.

Other InformationHide

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 Mottanaite-(Ce)Hide

References for Mottanaite-(Ce)Hide

Localities for Mottanaite-(Ce)Hide

Showing 3 localities.

This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.
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Locality ListHide

- 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). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).

All localities listed without proper references should be considered as questionable.
Italy (TL)
 
  • Lazio
    • Metropolitan City of Rome Capital
      • Campagnano di Roma
Ventura et al. (2002)
    • Viterbo Province
      • Vetralla
M.E. Ciriotti (2006) +1 other reference
Locality description
 
and/or  
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