Almeidaite (original) (raw)
A valid IMA mineral species
About AlmeidaiteHide
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Formula:
PbZn2(Mn,Y)(Ti,Fe3+)18O37(OH,O)
Name:
Named in 2013 by Luiz Albert Diaz Menezes Filho, L.A.D., N.V. Chukanov, Ramiza K. Rastsvetaeva, S.M. Aksenov, Igor Viktorovich Pekov, M.L.S.C. Chaves, R. Scholz, Daniel Atencio, P.R.G. Brandão, A.W. Romano, L.C.A. de Oliveira, J.D. Ardisson, K. Krambrock, R.L. Moreira, F.S. Guimarães, A.C. Persiano, and R. P. Richards in honor of Prof. Fernando Flávio Marques de Almeida [February 18, 1916 Rio de Janeiro, Brazil - August 2, 2013 São Paulo, Brazil]. Flávio Marques de Almeida is considered to be one of the most important Brazilian geologists. He was professor of geology at Institute for Technological Research, São Paulo about 1938-1939 until 1974. He became professor at the Institute of Geosciences, University of São Paulo, He was one of the founders of the Brazilian Society of Geology and the first chief editor of the Journal of Geology. His honors include: Vice-President of Géologique Société de France (1971); Medal Jose Bonifacio - Society Brazilian Geology (1964), Grand Cross of the National Order of Scientific Merit (1995), Doctor Honoris Causa State University of Campinas (1991), Medal of Merit Council Federal Engineering and Architecture (1995).
The Zn analogue of senaite and Pb analogue of landauite. ZnMn-analogue of cleusonite. PbZn-analogue of crichtonite. Chemically somewhat similar to nežilovite.
Almeidaite is a member of the crichtonite group with Pb dominant in the A site (with 12-fold coordination, located in the cubic layer, _M_0) and Zn dominant in the T site (with 4-fold, i.e., tetrahedral coordination). The anionic cp (close packed) framework has 9 layers along c in the chhchh sequence.
Unique IdentifiersHide
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Long-form identifier:
mindat:1:1:43884:7
1c382261-3629-400e-b26c-ba733cc7dbe2
IMA Classification of AlmeidaiteHide
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IMA Formula:
PbZn2(Mn,Y)(Ti,Fe3+)18O36(OH,O)2
Type description reference:
Menezes Filho, Luiz A. D., Chukanov, Nikita V., Rastsvetaeva, Ramiza K., Aksenov, Sergey M., Pekov, Igor V., Chaves, Mário L. S. C., Richards, R. Peter, Atencio, Daniel, Brandão, Paulo R. G., Scholz, Ricardo, Krambrock, Klaus, Moreira, Roberto L., Guimarães, Frederico S., Romano, Antônio W., Persiano, Aba C., de Oliveira, Luiz C. A., Ardisson, José D. (2015) Almeidaite, Pb(Mn,Y)Zn2(Ti,Fe3+)18O36(O,OH)2, a new crichtonite-group mineral, from Novo Horizonte, Bahia, Brazil. Mineralogical Magazine, 79 (2) 269-283 doi:10.1180/minmag.2015.079.2.06
Classification of AlmeidaiteHide
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4.00.
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
0 :
0 :
Mineral SymbolsHide
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As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference |
|---|---|---|
| Amd | 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 AlmeidaiteHide
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Density:
4.68(5) g/cm3 (Measured) 4.616 g/cm3 (Calculated)
Optical Data of AlmeidaiteHide
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Reflectivity:
| Wavelength | R1 | R2 |
|---|---|---|
| 400nm | 12.84% | 15.45% |
| 420nm | 12.79% | 15.39% |
| 440nm | 12.77% | 15.36% |
| 460nm | 12.79% | 15.35% |
| 470nm | 12.78% | 15.39% |
| 480nm | 12.80% | 15.39% |
| 500nm | 12.77% | 15.34% |
| 520nm | 12.83% | 15.41% |
| 540nm | 12.84% | 15.41% |
| 546nm | 12.86% | 15.43% |
| 560nm | 12.89% | 15.48% |
| 580nm | 12.85% | 15.42% |
| 589nm | 12.91% | 15.55% |
| 600nm | 12.96% | 15.63% |
| 620nm | 12.99% | 15.67% |
| 640nm | 13.02% | 15.73% |
| 650nm | 13.04% | 15.75% |
| 660nm | 13.09% | 15.81% |
| 680nm | 13.11% | 15.86% |
| 700nm | 13.16% | 15.94% |
Graph shows reflectance levels at different wavelengths (in nm). Top of box is 100%. Peak reflectance is 15.94%.
R1 shown in black, R2 shown in red
Chemistry of AlmeidaiteHide
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Mindat Formula:
PbZn2(Mn,Y)(Ti,Fe3+)18O37(OH,O)
Common Impurities:
Fe,Y,Sr,(Ca,La)
Crystallography of AlmeidaiteHide
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Class (H-M):
3 - Rhombohedral
Cell Parameters:
a = 10.4359(2) Å, c = 21.0471(4) Å
Morphology:
Platy crystals flattened on [0001],dominated by the basal pinacoid {0001}, which is bounded by various, mostly steep, rhombohedra and the hexagonal prism {1120}.
Twinning:
Multiply twinned, with non-planar contact surfaces that are approximately parallel to the c axis.
Crystal StructureHide
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| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0020510 | Almeidaite | Kastsvetaeva R K, Aksenov S M, Chukanov N V, Menezes L A D (2014) Crystal structure of almeidaite, a new mineral of the crichtonite group Doklady Chemistry 455 53-57 | 2014 | Novo Horizonte, Bahia, Brazil | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder DiffractionHide
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Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.436 Å | (48) |
| 3.074 Å | (50) |
| 3.023 Å | (50) |
| 2.907 Å | (100) |
| 2.781 Å | (44) |
| 2.492 Å | (55) |
| 2.157 Å | (55) |
| 1.615 Å | (50) |
Comments:
From Type Description.
Geological EnvironmentHide
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Type Occurrence of AlmeidaiteHide
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General Appearance of Type Material:
Isolated, black platy crystals up to 30 × 30 × 6 mm in size.
Place of Conservation of Type Material:
Type material is deposited in the collections of the collections of the Museu de Geociencias, Instituto de Geociencias, Universidade de Saõ Paulo, Saõ Paulo, Brazil, registration number DR744
Associated Minerals at Type Locality:
Reference:
Menezes Filho, L.A.D., Chukanov, N.V., Rastsvetaeva, R.K., Aksenov, S.M., Pekov, I.V., Chaves, M.L.S.C., Richards, R.P., Atencio, D., Brandão, P.R.G., Scholz, R., Krambrock, K., Moreira, R.L., Guimarães, F.S., Romano, A.W., Persiano, A.C., de Oliveira, L.C.A., Ardisson, J.D. (2015) Almeidaite, Pb(Mn,Y)Zn2(Ti,Fe3+)18O36(O,OH)2, a new crichtonite-group mineral, from Novo Horizonte, Bahia, Brazil. Mineralogical Magazine: 79: 269–283.
Synonyms of AlmeidaiteHide
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Relationship of Almeidaite to other SpeciesHide
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Other Members of this group:
| Botuobinskite | SrFe2+Mg2(Cr3+6Ti4+12)[O36(OH)2] | Trig. 3 : _R_3 |
|---|---|---|
| Cleusonite | (Pb,Sr)(U4+,U6+)(Fe2+,Zn)2(Ti,Fe2+,Fe3+)18(O,OH)38 | Trig. 3 : _R_3 |
| Crichtonite | Sr(Mn,Y,U)Fe2(Ti,Fe,Cr,V)18(O,OH)38 | Trig. 3 : _R_3 |
| Davidite-(Ce) | Ce(Y,U)Fe2(Ti,Fe,Cr,V)18(O,OH,F)38 | Trig. 3 : _R_3 |
| Davidite-(La) | La(Y,U)Fe2(Ti,Fe,Cr,V)18(O,OH,F)38 | Trig. 3 : _R_3 |
| Davidite-(Y) | (La,Ce,Na,Ca,Pb)(Y,Fe2+,◻)(Fe2+,Mn2+)2(Ti,Fe3+,Nb,Zr)18O38 (hypothetical) | Trig. |
| Dessauite-(Y) | (Sr,Pb)(Y,U)(Ti,Fe3+)20O38 | Trig. 3 : _R_3 |
| Gramaccioliite-(Y) | (Pb,Sr)(Y,Mn)Fe3+2(Ti,Fe3+)18O38 | Trig. 3 : _R_3 |
| Haitaite-(La) | LaU4+Fe3+2(Ti13Fe2+4Fe3+)O38 | Trig. 3 : _R_3 |
| Landauite | NaMnZn2(Ti,Fe)6Ti12O38 | Trig. 3 : _R_3 |
| Lindsleyite | (Ba,Sr)(Zr,Ca)(Fe,Mg)2(Ti,Cr,Fe)18O38 | Trig. |
| Loveringite | (Ca,Ce,La)(Zr,Fe)(Mg,Fe)2(Ti,Fe,Cr,Al)18O38 | Trig. 3 : _R_3 |
| Mapiquiroite | (Sr,Pb)(U,Y)Fe2(Ti,Fe3+,Cr3+)18O38 | Trig. 3 : _R_3 |
| Mathiasite | (Mg,Cr,Fe,Ca,K)2(Ti,Zr,Cr,Fe)5O12 | Trig. 3 : _R_3 |
| Mianningite | (◻,Pb,Ce,Na)(U4+,Mn,U6+)Fe3+2 (Ti,Fe3+)18O38 | Trig. 3 : _R_3 |
| Mirnyite | SrZr4+Mg2(Cr3+6Ti4+12)O38 | Trig. 3 : _R_3 |
| Paseroite | PbMn2+(Mn2+,Fe3+)2(V5+,Ti,◻)18O38 | Trig. 3 : _R_3 |
| Saranovskite | SrCaFe2+2(Cr4Ti2)Ti12O38 | Trig. 3 : _R_3 |
| Senaite | Pb(Mn,Y,U)(Fe,Zn)2(Ti,Fe,Cr,V)18(O,OH)38 | Trig. 3 : _R_3 |
| UM1987-03-O:FePbTiU | ~(U,Pb)(Ti,Fe3+,Fe2+,Mn)21O38 | Trig. 3 : _R_3 |
| UM2003-08-O:AlCaFeREEScTiV | (Ca,Ce)Sc(Ti,V,Fe,Al)20O38 | |
| UM2006-05-O:CaFeKMnNaREESrTiZr | (Sr,Na,K,REE)(Ca,Zr,Mn)(Ti,Fe)18Fe2O38 | |
| UM2006-06-O:CaFeKMnNaREESrTiZr | (Sr,Na,K,REE)(Zr,Ca,Mn)(Ti,Fe)18Fe2O38 | |
| UM2006-07-O:CaFeKMnNaREESrTiZr | (Na,Sr,K,REE)(Ca,Zr,Mn)(Ti,Fe)18Fe2O38 | |
| UM2006-08-O:CaFeKMnNaREESrTiZr | (Na,Sr,K,REE)(Zr,Ca,Mn)(Ti,Fe)18Fe2O38 | |
| UM2006-09-O:CaFeMnREESrTiZr | (Ce,Sr,REE)(Ca,Mn,Zr)Fe2(Ti,Fe)18O38 | |
| Unnamed (HBU UK-4) | NaFe2+Zn2(Ti,Fe3+,Nb)6Ti12O38 | Trig. 3 : _R_3 |
Related Minerals - Strunz-mindat GroupingHide
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| 4.00. | Goethite | α-Fe3+O(OH) | Orth. m m m _(_2/_m_2/_m_2/m ) |
|---|---|---|---|
| 4.00. | Microlite Group | A2-mTa2X6-wZ-n | Iso. m_3_m _(_4/_m_32/m ) : F d_3_m |
| 4.00. | Ferrotaaffeite-6N'3S | (Be,Zn,Mg)FeAl4O8 | Trig. 3_m_ _(_32/m ) : R_3_m |
| 4.00. | Pyrochlore Group | A2Nb2(O,OH)6Z | |
| 4.00. | Písekite-(Y) | (Y,As,Ca,Fe,U)(Nb,Ti,Ta)O4 | |
| 4.00. | UM2004-19-O:AlCeGdZr | (Gd,Ce)4Al2Zr4O17 | |
| 4.00. | UM2004-21-O:CaFeGdZr | Ca2Gd4Fe5ZrO15 | |
| 4.00. | UM2004-27-O:GdTi | Gd2Ti4O11 | |
| 4.00. | Mapiquiroite | (Sr,Pb)(U,Y)Fe2(Ti,Fe3+,Cr3+)18O38 | Trig. 3 : _R_3 |
| 4.00. | Vapnikite | Ca2CaUO6 | Mon. 2/m |
Fluorescence of AlmeidaiteHide
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Non-fluorescent in long-wave or short-wave UV
Other InformationHide
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IR Spectrum:
The main absorption bands of the IR spectrum (cm-1, s = strong, sh = shoulder, w = weak) are: 3340 (O-H stretching vibrations), 1099w, 1041w, 1012w (overtones and Zn-OH bending vibrations), 695sh, 574s, 534s, 485sh (stretching vibrations in octahedra and tetrahedra).
Notes:
Metamict due to trace Th; Mössbauer spectroscopy indicates almost all Fe is trivalent.
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 AlmeidaiteHide
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References for AlmeidaiteHide
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Reference List:
Menezes Filho, Luiz A. D., Chukanov, Nikita V., Rastsvetaeva, Ramiza K., Aksenov, Sergey M., Pekov, Igor V., Chaves, Mário L. S. C., Richards, R. Peter, Atencio, Daniel, Brandão, Paulo R. G., Scholz, Ricardo, Krambrock, Klaus, Moreira, Roberto L., Guimarães, Frederico S., Romano, Antônio W., Persiano, Aba C., de Oliveira, Luiz C. A., Ardisson, José D. (2015) Almeidaite, Pb(Mn,Y)Zn2(Ti,Fe3+)18O36(O,OH)2, a new crichtonite-group mineral, from Novo Horizonte, Bahia, Brazil. Mineralogical Magazine, 79 (2) 269-283 doi:10.1180/minmag.2015.079.2.06
Localities for AlmeidaiteHide
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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.
Locality ListHide
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