Armellinoite-(Ce)
A valid IMA mineral species
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Gianluca Armellino at the Valletta mine - August 2014
Formula:
Ca4Ce4+(AsO4)4 · H2O
Colour:
pale yellow to brown–yellow; also honey-yellow, canary-yellow, yellow-greenish, yellow-brown
Lustre:
Vitreous, Resinous
Hardness:
3 - 3½
Specific Gravity:
4.29 (Calculated)
Crystal System:
Tetragonal
Name:
The name honours Gianluca Armellino (born 1962) of Millesimo (Liguria, Italy). Mr. Armellino is an avid and sophisticated researcher and systematic collector specializing in the minerals of Liguria and other specific localities, with specimens only personally collected.
He is the discoverer of this new species and the co-discoverer of poppiite, cortesognoite, molinelloite and piccoliite. Mr. Armellino is also the one who first found more than 80 mineral species new for Italian regions. Some of them [arsenogoyazite, bariopharmacoalumite, barnesite, brandtite, calderónite, čechite, duttonite, franciscanite, gageite, hummerite, natrodufrénite, norrishite, pyrochroite, roscoelite, schröckingerite, talmessite, and wakefieldite-(Y)] represented the first discovery for Italy or Europe.
He is the discoverer of this new species and the co-discoverer of poppiite, cortesognoite, molinelloite and piccoliite. Mr. Armellino is also the one who first found more than 80 mineral species new for Italian regions. Some of them [arsenogoyazite, bariopharmacoalumite, barnesite, brandtite, calderónite, čechite, duttonite, franciscanite, gageite, hummerite, natrodufrénite, norrishite, pyrochroite, roscoelite, schröckingerite, talmessite, and wakefieldite-(Y)] represented the first discovery for Italy or Europe.
Type Locality:
Isostructural with:
One of five currently (2026) recognized minerals with essential tetravalent cerium, beside dyrnaesite-(La), stetindite-(Ce), cerianite-(Ce) and anningite-(Ce).
Type material contains tiny pale yellow to brown-yellow, pseudo-octahedral crystals embedded in associated quartz +/- hematite +/- muscovite +/- cryptomelane matrix.
Type material contains tiny pale yellow to brown-yellow, pseudo-octahedral crystals embedded in associated quartz +/- hematite +/- muscovite +/- cryptomelane matrix.
Unique Identifiers
Mindat ID:
53219
Long-form identifier:
mindat:1:1:53219:8
IMA Classification of Armellinoite-(Ce)
Classification of Armellinoite-(Ce)
8.CG.25
8 : PHOSPHATES, ARSENATES, VANADATES
C : Phosphates without additional anions, with H2O
G : With large and medium-sized cations, RO4:H2O = 1:1
8 : PHOSPHATES, ARSENATES, VANADATES
C : Phosphates without additional anions, with H2O
G : With large and medium-sized cations, RO4:H2O = 1:1
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 |
|---|---|---|
| Aml-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 Armellinoite-(Ce)
Vitreous, Resinous
Transparency:
Translucent
Comment:
resinous to vitreous
Colour:
Pale yellow to brown–yellow; also honey-yellow, canary-yellow, yellow-greenish, yellow-brown
Streak:
White
Hardness:
3 - 3½ on Mohs scale
Tenacity:
Brittle
Cleavage:
Imperfect/Fair
|| {110} and {100}
|| {110} and {100}
Fracture:
Irregular/Uneven
Density:
4.29 g/cm3 (Calculated)
Optical Data of Armellinoite-(Ce)
Type:
Uniaxial (-)
RI values:
nω = 1.795(5) nε = 1.765(5)
Max. Birefringence:
δ = 0.030
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.
Pleochroism:
Non-pleochroic
Chemistry of Armellinoite-(Ce)
Mindat Formula:
Ca4Ce4+(AsO4)4 · H2O
Element Weights:
Crystallography of Armellinoite-(Ce)
Crystal System:
Tetragonal
Class (H-M):
4/m - Dipyramidal
Space Group:
I41/a
Setting:
I41/a
Cell Parameters:
a = 10.749(2) Å, b = 10.749(2) Å, c = 12.030(2) Å
Ratio:
a:b:c = 1 : 1 : 1.119
Unit Cell V:
1390 ų
Z:
4
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 7.983 Å | (36) |
| 4.443 Å | (23) |
| 2.957 Å | (100) |
| 2.398 Å | (14) |
| 1.875 Å | (22) |
| 1.728 Å | (19) |
| 1.612 Å | (13) |
| 1.475 Å | (26) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47e : [Vanadates, chromates, manganates] |
Type Occurrence of Armellinoite-(Ce)
General Appearance of Type Material:
pseudo-octahedral crystal embedded in matrix; easily confused with titanite.
Place of Conservation of Type Material:
Type material is deposited in the mineralogical collections of the Museo delle Collezioni di Mineralogia, Gemmologia, Petrologia e Giacimentologia, Dipartimento di Scienze della Terra “A. Desio”, Università di Milano, catalogue number MCMGPG-H2018-003
Geological Setting of Type Material:
Fe–Mn ore in metaquartzites
Associated Minerals at Type Locality:
Synonyms of Armellinoite-(Ce)
Other Language Names for Armellinoite-(Ce)
Related Minerals - Strunz-mindat Grouping
| 8.CG. | Fluckite | CaMn2+(AsO3OH)2 · 2H2O |
| 8.CG. | Dondoellite | Ca2Fe(PO4)2 · 2H2O |
| 8.CG. | 'Ca-Huréaulite' | CaMn5(PO4)4 · 4H2O |
| 8.CG. | Alumolukrahnite | Ca[CuAl](AsO4)2(H2O,OH)2 |
| 8.CG.05 | Parabrandtite | Ca2Mn2+(AsO4)2 · 2H2O |
| 8.CG.05 | Talmessite | Ca2Mg(AsO4)2 · 2H2O |
| 8.CG.05 | Collinsite | Ca2Mg(PO4)2 · 2H2O |
| 8.CG.05 | Messelite | Ca2Fe2+(PO4)2 · 2H2O |
| 8.CG.05 | Gaitite | Ca2Zn(AsO4)2 · 2H2O |
| 8.CG.05 | Anorthoroselite | Ca2Co(AsO4)2 · 2H2O |
| 8.CG.05 | Cassidyite | Ca2Ni(PO4)2 · 2H2O |
| 8.CG.05 | Fairfieldite | Ca2Mn2+(PO4)2 · 2H2O |
| 8.CG.05 | Hillite | Ca2Zn(PO4)2 · 2H2O |
| 8.CG.05 | 'Unnamed (Fe2+-analogue of Parabrandtite)' | Ca2Fe2+(AsO4)2 · 2H2O |
| 8.CG.10 | Zincroselite | Ca2Zn(AsO4)2 · 2H2O |
| 8.CG.10 | Roselite | Ca2Co(AsO4)2 · 2H2O |
| 8.CG.10 | Rruffite | Ca2Cu(AsO4)2 · 2H2O |
| 8.CG.10 | Wendwilsonite | Ca2Mg(AsO4)2 · 2H2O |
| 8.CG.10 | Brandtite | Ca2Mn2+(AsO4)2 · 2H2O |
| 8.CG.10 | 'Unnamed (Fe2+-analogue of Brandtite)' | Ca2Fe2+(AsO4)2 · 2H2O |
| 8.CG.15 | Mawbyite | PbFe3+2(AsO4)2(OH)2 |
| 8.CG.15 | Thometzekite | PbCu2+2(AsO4)2 · 2H2O |
| 8.CG.15 | Yancowinnaite | PbCuAl(AsO4)2OH · H2O |
| 8.CG.15 | Schneebergite | BiCo2(AsO4)2(OH) · H2O |
| 8.CG.15 | Cabalzarite | CaMg2(AsO4)2 · 2H2O |
| 8.CG.15 | Nickelschneebergite | BiNi2(AsO4)2(OH) · H2O |
| 8.CG.15 | Lotharmeyerite | CaZn2(AsO4)2 · 2H2O |
| 8.CG.15 | Nickeltsumcorite | Pb(Ni,Fe3+)2(AsO4)2(H2O,OH)2 |
| 8.CG.15 | Magnesiofluckite | CaMg(AsO3OH)2(H2O)2 |
| 8.CG.15 | Krettnichite | PbMn3+2(VO4)2(OH)2 |
| 8.CG.15 | Cobalttsumcorite | PbCo2(AsO4)2 · 2H2O |
| 8.CG.15 | Manganlotharmeyerite | CaMn3+2(AsO4)2(OH)2 |
| 8.CG.15 | Tsumcorite | PbZn2(AsO4)2 · 2H2O |
| 8.CG.15 | Ferrilotharmeyerite | CaZnFe3+(AsO4)2(OH) · H2O |
| 8.CG.15 | Cobaltlotharmeyerite | CaCo2(AsO4)2 · 2H2O |
| 8.CG.15 | Mounanaite | PbFe3+2(VO4)2(OH)2 |
| 8.CG.15 | Nickellotharmeyerite | CaNi2(AsO4)2 · 2H2O |
| 8.CG.20 | Lukrahnite | CaCuFe3+(AsO4)2(OH,H2O)2 |
| 8.CG.20 | Helmutwinklerite | PbZn2(AsO4)2 · 2H2O |
| 8.CG.20 | Phosphogartrellite | PbCuFe3+(PO4)2(OH,H2O)2 |
| 8.CG.20 | Gartrellite | PbCuFe3+(AsO4)2(OH) · H2O |
| 8.CG.20 | Zincgartrellite | PbZn2(AsO4)2(H2O,OH)2 |
| 8.CG.20 | Rappoldite | PbCo2(AsO4)2 · 2H2O |
| 8.CG.25 | Pottsite | (Pb3xBi4-2x)(VO4)4 · H2O (0.8 < x < 1.0) |
| 8.CG.35 | Nickeltalmessite | Ca2Ni(AsO4)2 · 2H2O |
| 8.CG.55 | Irhtemite | Ca4Mg(AsO4)2(HAsO4)2 · 4H2O |
Fluorescence of Armellinoite-(Ce)
Other Information
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 Armellinoite-(Ce)
mindat.org URL:
https://www.mindat.org/min-53219.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Armellinoite-(Ce)
Reference List:
Hålenius, Ulf, Hatert, Frédéric, Pasero, Marco, Mills, Stuart J. (2018) IMA Commission on New Minerals, Nomenclature and Classification (CNMNC) NEWSLETTER 46. European Journal of Mineralogy, 30 (6) 1181-1189 doi:10.1127/ejm/2018/0030-2819
Cámara, Fernando, Ciriotti, Marco E., Kolitsch, Uwe, Bosi, Ferdinando, Bittarello, Erica, Brizio, Piero, Vignola, Pietro, Blaß, Günter (2021) Armellinoite-(Ce), Ca4Ce4+(AsO4)4⋅H2O, a new mineral species isostructural with pottsite, (Pb3Bi)Bi(VO4)4⋅H2O. Mineralogical Magazine, 85 (6) 901-909 doi:10.1180/mgm.2021.84
Localities for Armellinoite-(Ce)
Showing 1 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.
Italy (TL) | |
| Hålenius et al. (2018) +1 other reference |
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