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Obertiite Root Name Group

A group of related mineral species

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Photos of Obertiite Root Name Group (26)Discuss Obertiite Root Name Group

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Edit Obertiite Root Name Group Add Synonym Edit CIF structures Clear Cache

Ferri-obertiite

Caspar quarry, Ettringen, Vordereifel, Mayen-Koblenz, Rhineland-Palatinate, Germany

Ferri-obertiite

Rothenberg Quarry, Bell, Mendig, Mayen-Koblenz, Rhineland-Palatinate, Germany

Ferri-obertiite

Rothenberg Quarry, Bell, Mendig, Mayen-Koblenz, Rhineland-Palatinate, Germany

Ferri-obertiite

Caspar quarry, Ettringen, Vordereifel, Mayen-Koblenz, Rhineland-Palatinate, Germany

Ferri-obertiite

Rothenberg Quarry, Bell, Mendig, Mayen-Koblenz, Rhineland-Palatinate, Germany

Ferri-obertiite

Rothenberg Quarry, Bell, Mendig, Mayen-Koblenz, Rhineland-Palatinate, Germany

Ferri-obertiite

Caspar quarry, Ettringen, Vordereifel, Mayen-Koblenz, Rhineland-Palatinate, Germany

Ferri-obertiite

Rothenberg Quarry, Bell, Mendig, Mayen-Koblenz, Rhineland-Palatinate, Germany

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About Obertiite Root Name GroupHide

Roberta Oberti

Formula:

ANa₂(C²⁺₃C³⁺Ti)Si₈O₂₂O₂

The obertiite minerals are ^WO^2- dominant amphiboles defined with :
^A(Na+K+2Ca)> 0.5 apfu,
^B: Na dominant
^CTi > 0.5 apfu and
^WO > 1.0 apfu

The root-name mineral, obertiite is defined with Na, Mg, Al as the dominant elements in the A and C positions respectively. Obertiite minerals with other dominant elements are named with pre-fixes in accordance with the guidelines established in the 2012 amphibole nomenclature.

Member of:

w(O)-dominant Amphibole Group > Amphibole Supergroup

Name:

The obertiite root name is for Prof. Roberta Oberti, University of Pavia, Italy, for her contributions to the crystal chemistry of amphiboles.

Naturally occurring obertiite minerals from the Eifel area show a variable composition in the mangani-obertiite/ferri-obertiite/ferro-ferri-obertiite range and the following Fe:Mn ratio ranges have been determined by WDS/EDS analyses:

Bellerberg: 8 samples with Fe:Mn between 4:1 and 3:2
Emmelberg: 1 sample with Fe:Mn = 3:1
Herchenberg: 1 sample with Fe:Mn = 4:1
Nickenicher Sattel: 1 sample with Fe:Mn = 3:1
Nick. Weinberg 1 sample with Fe:Mn = 3:1
Wannenköpfe: 1 sample with Fe:Mn = 3:1
Rothenberg: 6 samples with Fe:Mn between 3:1 and 3:2 (1 sample 1.6:1.5)
In addition, one sample from Caspar quarry shows a Fe:Mn ratio of ~ 7:1 (EMPA data).

Data from Günter Blaß and Christof Schäfer (2014).

Unique IdentifiersHide

Mindat ID:

46446

Long-form identifier:

mindat:1:1:46446:2

Chemistry of Obertiite Root Name GroupHide

Mindat Formula:

ANa₂(C²⁺₃C³⁺Ti)Si₈O₂₂O₂

The obertiite minerals are ^WO^2- dominant amphiboles defined with :
^A(Na+K+2Ca)> 0.5 apfu,
^B: Na dominant
^CTi > 0.5 apfu and
^WO > 1.0 apfu

The root-name mineral, obertiite is defined with Na, Mg, Al as the dominant elements in the A and C positions respectively. Obertiite minerals with other dominant elements are named with pre-fixes in accordance with the guidelines established in the 2012 amphibole nomenclature.

Crystal StructureHide

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Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure

ID	Species	Reference	Link	Year	Locality	Pressure (GPa)	Temp (K)
0002347	Ferri-obertiite	Hawthorne F C, Cooper M A, Grice J D, Ottolini L (2000) A new anhydrous amphibole from the Eifel region, Germany: Description and crystal structure of obertiite, NaNa2(Mg3FeTi)Si8O22O2 American Mineralogist 85 236-241		2000	Eifel region, Germany	0	293
0002347	Mangani-obertiite	Hawthorne F C, Cooper M A, Grice J D, Ottolini L (2000) A new anhydrous amphibole from the Eifel region, Germany: Description and crystal structure of obertiite, NaNa2(Mg3FeTi)Si8O22O2 American Mineralogist 85 236-241		2000	Eifel region, Germany	0	293

CIF Raw Data - click here to close

data_global
_chemical_name_mineral 'Ferri-obertiite'
loop_
_publ_author_name
'Hawthorne F C'
'Cooper M A'
'Grice J D'
'Ottolini L'
_journal_name_full 'American Mineralogist'
_journal_volume 85 
_journal_year 2000
_journal_page_first 236
_journal_page_last 241
_publ_section_title
;
 A new anhydrous amphibole from the Eifel region, Germany:
 Description and crystal structure of obertiite, NaNa2(Mg3FeTi)Si8O22O2
 Note: M1A and M1 are interchanged in the bond length table
;
_database_code_amcsd 0002347
_chemical_compound_source 'Eifel region, Germany'
_chemical_formula_sum 'O24 Si8 Ti.86 Mn.37 Mg2.13 Fe.71 Al.03 Na2.66 Ca2 K.18'
_cell_length_a 9.776
_cell_length_b 17.919
_cell_length_c 5.292
_cell_angle_alpha 90
_cell_angle_beta 104.05
_cell_angle_gamma 90
_cell_volume 899.299
_exptl_crystal_density_diffrn      3.363
_symmetry_space_group_name_H-M 'C 1 2/m 1'
loop_
_space_group_symop_operation_xyz
  'x,y,z'
  '1/2+x,1/2+y,z'
  'x,-y,z'
  '1/2+x,1/2-y,z'
  '-x,y,-z'
  '1/2-x,1/2+y,-z'
  '-x,-y,-z'
  '1/2-x,1/2-y,-z'
loop_
_atom_site_label
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_occupancy
_atom_site_U_iso_or_equiv
O1   0.11360   0.08580   0.21760   1.00000 ?
O2   0.11700   0.16520   0.72490   1.00000 ?
O3   0.10340   0.00000   0.70610   1.00000 ?
O4   0.35780   0.25080   0.79950   1.00000 ?
O5   0.34970   0.12760   0.08050   1.00000 ?
O6   0.34610   0.12000   0.57980   1.00000 ?
O7   0.34340   0.00000   0.29960   1.00000 ?
SiT1   0.28360   0.08524   0.29410   1.00000 ?
SiT2   0.28830   0.17078   0.79850   1.00000 ?
Ti1A   0.00000   0.07880   0.50000   0.43000 ?
Mn1A   0.00000   0.07880   0.50000   0.18500 ?
Mg1   0.00000   0.09100   0.50000   0.38500 ?
Mg2   0.00000   0.18172   0.00000   0.66000 ?
Fe2   0.00000   0.18172   0.00000   0.32500 ?
Al2   0.00000   0.18172   0.00000   0.01500 ?
Mg3   0.00000   0.00000   0.00000   0.04000 ?
Na4   0.00000   0.27380   0.50000   0.92000 ?
Fe4   0.00000   0.27380   0.50000   0.03000 ?
Ca4   0.00000   0.27380   0.50000   1.00000 ?
KAm   0.04800   0.50000   0.10100   0.09000   0.02000
NaAm   0.04800   0.50000   0.10100   0.19000   0.02000
NaA2   0.00000   0.48860   0.00000   0.22000   0.02000
loop_
_atom_site_aniso_label
_atom_site_aniso_U_11
_atom_site_aniso_U_22
_atom_site_aniso_U_33
_atom_site_aniso_U_12
_atom_site_aniso_U_13
_atom_site_aniso_U_23
O1 0.00620 0.00470 0.00910 0.00000 0.00070 0.00050
O2 0.00520 0.01280 0.00400 0.00000 0.00010 -0.00070
O3 0.00540 0.01270 0.00430 0.00000 0.00210 0.00000
O4 0.01150 0.00680 0.01110 0.00120 0.00050 -0.00360
O5 0.00690 0.01300 0.00750 0.00490 0.00300 -0.00080
O6 0.00840 0.01050 0.00660 -0.00460 0.00030 -0.00010
O7 0.00990 0.00870 0.01380 0.00000 0.00510 0.00000
SiT1 0.00580 0.00550 0.00500 -0.00040 0.00130 0.00080
SiT2 0.00510 0.00630 0.00400 0.00030 0.00010 -0.00080
Ti1A 0.00940 0.00940 0.00470 0.00000 0.00020 0.00000
Mn1A 0.00940 0.00940 0.00470 0.00000 0.00020 0.00000
Mg1 0.00940 0.00940 0.00470 0.00000 0.00020 0.00000
Mg2 0.00770 0.00840 0.00690 0.00000 0.00240 0.00000
Fe2 0.00770 0.00840 0.00690 0.00000 0.00240 0.00000
Al2 0.00770 0.00840 0.00690 0.00000 0.00240 0.00000
Mg3 0.00680 0.00820 0.00810 0.00000 0.00070 0.00000
Na4 0.02400 0.01590 0.02530 0.00000 0.01600 0.00000
Fe4 0.02400 0.01590 0.02530 0.00000 0.01600 0.00000
Ca4 0.02400 0.01590 0.02530 0.00000 0.01600 0.00000

Synonyms of Obertiite Root Name GroupHide

Sodic amphibole (in part)

Relationship of Obertiite Root Name Group to other SpeciesHide

Member of:

w(O)-dominant Amphibole Group > Amphibole Supergroup

Other Members of w(O)-dominant Amphibole Group:

Kaersutite Root Name Group	ACa₂(Z²⁺₃Z³⁺Ti)(Si₆Al₂O₂₂)O₂	Mon.
Mangani-dellaventuraite	NaNa₂(MgMn³⁺₂Ti⁴⁺Li)Si₈O₂₂O₂	Mon. 2/m : B2/m
Mangano-mangani-ungarettiite	NaNa₂(Mn²⁺₂Mn³⁺₃)(Si₈O₂₂)O₂	Mon. 2/m : B2/m
Oxo-magnesio-hastingsite	NaCa₂(Mg₃(Fe³⁺_2-x,Ti_x))₅(Si₆Al₂O₂₂)O₂	Mon. 2/m : B2/m
Oxo-mangani-leakeite	NaNa₂(Mn³⁺₄Li)Si₈O₂₂O₂	Mon. 2/m : B2/m
'Oxo-pargasite'	NaCa₂(Mg₃(Al_2-xTi_x))₅(Si₆Al₂O₂₂)O₂
Potassic-jeanlouisite	K(NaCa)(Mg₄Ti)Si₈O₂₂O₂	Mon. 2/m : B2/m
'Potassic-mangano-mangani-ungarettiite'	KNa₂(Mn²⁺₂Mn³⁺₃)Si₈O₂₂O₂

Obertiite Root Name Group Members:

Ferri-obertiite	NaNa₂(Mg₃Fe³⁺Ti)Si₈O₂₂O₂	Mon. 2/m : B2/m
Ferro-ferri-obertiite	NaNa₂(Fe²⁺₃Fe³⁺Ti)Si₈O₂₂O₂	Mon. 2/m : B2/m
Mangani-obertiite	NaNa₂(Mg₃Mn³⁺Ti⁴⁺)Si₈O₂₂O₂	Mon. 2/m : B2/m
'Unnamed (Possible K-analogue of Ferri-obertiite)'	KNa₂((Mg,Fe,Na)₃Fe³⁺(Ti,Fe))Si₈O₂₂(O,F)₂

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 Obertiite Root Name GroupHide

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References for Obertiite Root Name GroupHide

Reference List:

IMA Approvals - August 2009

Oberti, Roberta, Ungaretti, Luciano, Cannillo, Elio, Hawthorne, Frank C. (1992) The behaviour of Ti in amphiboles: I. Four- and six-coordinate Ti in richterite. European Journal of Mineralogy, 4 (3) 425-440 doi:10.1127/ejm/4/3/0425

Hawthorne, Frank C., Cooper, Mark A., Grice, Joel D., Ottolini, Luisa (2000) A new anhydrous amphibole from the Eifel region, Germany: Description and crystal structure of obertiite, NaNa₂(Mg₃Fe³⁺Ti⁴⁺)Si₈O₂₂O₂. American Mineralogist, 85 (1) 236-241 doi:10.2138/am-2000-0124

Hawthorne, F. C., Ball, N. A., Czamanske, G. K. (2010) Ferro-obertiite, NaNa₂(Fe²⁺₃Fe³⁺Ti)Si₈O₂₂O₂, a new mineral species of the amphibole group from Coyote Peak, Humboldt County, California. The Canadian Mineralogist, 48 (2) 301-306 doi:10.3749/canmin.48.2.301

Hawthorne, F. C., Oberti, R., Harlow, G. E., Maresch, W. V., Martin, R. F., Schumacher, J. C., Welch, M. D. (2012) Nomenclature of the amphibole supergroup. American Mineralogist, 97 (11) 2031-2048 doi:10.2138/am.2012.4276

Oberti, R., Cannillo, E., Toscani, G. (2012) How to name amphiboles after the IMA2012 report: rules of thumb and a new PC program for monoclinic amphiboles. Periodico di Mineralogia: 81: 257-267.

Williams, P. A., Hatert, F., Pasero, M., Mills, S. J. (2014) IMA Commission on New Minerals, Nomenclature and Classification (CNMNC), CNMNC Newsletter No. 22. Mineralogical Magazine, 78 (5) 1241-1248 doi:10.1180/minmag.2014.078.5.10

Localities for Obertiite Root Name GroupHide

Showing 24 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.


Germany
Rhineland-Palatinate Ahrweiler Brohltal Burgbrohl ⓘ Herchenberg quarry	[Ferri-obertiite, Mangani-obertiite] Blaß et al. (2003)
Mayen-Koblenz Maifeld Ochtendung ⓘ Wannenköpfe Quarry	[Ferri-obertiite, Mangani-obertiite] Williams et al. (2014)
Mendig Bell ⓘ Rothenberg Quarry	[Ferri-obertiite] Hålenius et al. (2015) +2 other references
Pellenz Nickenich ⓘ Nickenicher Sattel	[Ferri-obertiite, Mangani-obertiite] Blaß et al. (2001) +1 other reference
ⓘ Nickenicher Weinberg	[Ferri-obertiite, Mangani-obertiite] Künzel et al. (2011)
Vordereifel Ettringen ⓘ Caspar quarry	[Ferri-obertiite, Ferro-ferri-obertiite, Mangani-obertiite] Hawthorne et al. (2000)
Vulkaneifel Daun Üdersdorf ⓘ Emmelberg	[Ferri-obertiite, Mangani-obertiite] Blaß et al. (2001) +1 other reference

Russia
Sakha Oymyakonsky District ⓘ Elga meteorite	[Ferri-obertiite] Sharygin (2020)

USA
California Humboldt County ⓘ Coyote Peak	[Ferro-ferri-obertiite] Hawthorne et al. (2010)
Virginia Augusta County West Augusta ⓘ Stoutameyer Branch (Stotameyer Creek)	[Ferri-obertiite] Robin D. Tibbit (deceased)

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