Ferri-obertiite
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About Ferri-obertiite
Roberta Oberti
Formula:
Na(Na2)(Mg3Fe3+Ti)(Si8O22)O2
Ferri-obertiite is a obertiite root name amphibole in the WO2- dominant amphibole group with Mg as the dominant element in the C2+ position and Fe3+ as the dominant element in the C3+ position.
Colour:
Pink-orange
Crystal System:
Monoclinic
Name:
The obertiite root name is for Prof. Roberta Oberti, University of Pavia, Italy, for her contributions to the crystal chemistry of amphiboles.
Type Locality:
The obertiite root name mineral published as obertiite (IMA 1998-046) was renamed ferri-obertiite in 2012. Re-investigation of the holotype material in 2014 revealed that Mn3+ > Fe3+, hence this mineral was renamed to mangani-obertiite.
Data provided by Günter Blaß show a wide range of Fe/Mn ratios in the obertiite root name minerals from the Eifel area. It is therefore likely that both ferri-obertiite and mangani-obertiite is present.
Ferri-obertiite was formally approved as a new mineral by IMA in 2015 (IMA 2015-079).
Possible K-analogue is known: Unnamed (possible K analogue of ferri-obertiite).
Data provided by Günter Blaß show a wide range of Fe/Mn ratios in the obertiite root name minerals from the Eifel area. It is therefore likely that both ferri-obertiite and mangani-obertiite is present.
Ferri-obertiite was formally approved as a new mineral by IMA in 2015 (IMA 2015-079).
Possible K-analogue is known: Unnamed (possible K analogue of ferri-obertiite).
Classification of Ferri-obertiite
Physical Properties of Ferri-obertiite
Colour:
Pink-orange
Optical Data of Ferri-obertiite
Type:
Biaxial (+)
RI values:
nα = 1.664 nβ = 1.680 nγ = 1.722
2V:
Measured: 66.4° (3), Calculated: 64.7°
Max Birefringence:
δ = 0.058
Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.
and does not take into account mineral colouration.
Surface Relief:
High
Chemical Properties of Ferri-obertiite
Formula:
Na(Na2)(Mg3Fe3+Ti)(Si8O22)O2
Ferri-obertiite is a obertiite root name amphibole in the WO2- dominant amphibole group with Mg as the dominant element in the C2+ position and Fe3+ as the dominant element in the C3+ position.
Ferri-obertiite is a obertiite root name amphibole in the WO2- dominant amphibole group with Mg as the dominant element in the C2+ position and Fe3+ as the dominant element in the C3+ position.
IMA Formula:
NaNa2(Mg3Fe3+Ti)Si8O22O2
Crystallography of Ferri-obertiite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/m
Setting:
C2/m
Cell Parameters:
a = 9.7901(7) Å, b = 17.935(1) Å, c = 5.2892(4) Å
β = 104.142(2)°
β = 104.142(2)°
Ratio:
a:b:c = 0.546 : 1 : 0.295
Unit Cell V:
900.58 ų
Z:
2
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 8.391 | (72) |
| 3.388 | (72) |
| 3.260 | (37) |
| 3.116 | (76) |
| 2.704 | (100) |
| 2.583 | (39) |
| 2.529 | (67) |
| 2.160 | (39) |
Type Occurrence of Ferri-obertiite
Place of Conservation of Type Material:
Type material is deposited in the collections of the Museo di Mineralogia, Dipartimento di Scienze della Terra e dell’Ambiente, Università di Pavia, catalogue number 2015–02.
Empirical Formula of Type Material:
A(Na0.76K0.22)Σ0.98B(Na1.61Ca0.35Mn2+0.04)Σ2.00C(Mg3.58Mn2+0.11Fe3+0.62Ti4+0.66Cr3+0.01Zn0.01Ni0.01)Σ5.00T(Si7.82Ti4+0.12Al0.06)Σ8.00O22W[O1.26F0.55(OH)0.19]Σ2.00
Geological Setting of Type Material:
Vesicles in a silicate vein in a basalt quarry
Associated Minerals at Type Locality:
Reference:
Oberti, R., Boiocchi, M., Hawthorne, F.C., Ball, N.A., Blass, G. (2017): Ferri-obertiite from the Rothenberg quarry, Eifel volcanic complex (Germany): mineral data and crystal-chemistry of a new amphibole end-member. Mineralogical Magazine: 81: 641–651.
Synonyms of Ferri-obertiite
Relationship of Ferri-obertiite to other Species
Other Members of this group:
| Ferro-ferri-obertiite | NaNa2(Fe2+3Fe3+Ti)Si8O22O2 | Mon. 2/m : B2/m |
| Mangani-obertiite | Na(Na2)(Mg3Mn3+Ti)(Si8O22)O2 | Mon. 2/m : B2/m |
| Unnamed (possible K-analogue of Ferri-obertiite) | KNa2[(Mg,Fe,Na)3Fe3+(Ti,Fe)]Si8O22(O,F)2 |
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.
References for Ferri-obertiite
Reference List:
Sort by Year (asc) | by Year (desc) | by Author (A-Z) | by Author (Z-A)
Oberti, R., Ungaretti, L., Cannillo, E., Hawthrone, F. (1992) The behavior of Ti in Amphiboles: I. Four- and six-coordinated Ti in Richterite, European Journal of Mineralogy: 4: 425-439.
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(Mg3,Fe,Ti)Si8O28O2. American Mineralogist: 85: 236-241.
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.
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: 2031–2048.
Oberti, R., Boiocchi, M., Hawthorne, F.C.,Ball, N.A. and Blass, G. (2015) Ferri-obertiite, IMA 2015-079. CNMNC Newsletter No. 28, December 2015, page 1863; Mineralogical Magazine: 79: 1859–1864
Oberti, R., Boiocchi, M., Hawthorne, F.C., Ball, N.A., Blass, G. (2017): Ferri-obertiite from the Rothenberg quarry, Eifel volcanic complex (Germany): mineral data and crystal-chemistry of a new amphibole end-member. Mineralogical Magazine: 81: 641–651.
Internet Links for Ferri-obertiite
mindat.org URL:
https://www.mindat.org/min-46414.html
Please feel free to link to this page.
Please feel free to link to this page.
External Links:
Mineral Dealers:
Localities for Ferri-obertiite
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for 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.
Germany | |
| Blass, G.; Graf, H.W., Neue Mineralienfunde aus der Vulkaneifel, Mineralien-Welt 1/2001 New minerals approved by IMA CNMNC in August-September 2014 |
| Hand Egon Künzel, Günter Blaß, Willi Schüller (2011) Mineralien - Bomben - Grottensteine: Der Nickenicher Weinberg. Lapis, 36, #7-8, 55-66 | |
| - New minerals approved by IMA CNMNC in August-September 2014 -Blass, G.; Graf, H.W., Neue Mineralienfunde aus der Vulkaneifel, Mineralien-Welt 1/2001 |
| in the collection of Christof Schäfer; Oberti, R., Boiocchi, M., Hawthorne, F.C., Ball, N.A., Blass, G. (2017): Ferri-obertiite from the Rothenberg quarry, Eifel volcanic complex (Germany): mineral data and crystal-chemistry of a new amphibole end-member. Mineralogical Magazine, 81, 641–651. |
| Oberti, R., Boiocchi, M., Hawthorne, F.C.,Ball, N.A. and Blass, G. (2015) Ferri-obertiite, IMA 2015-079. CNMNC Newsletter No. 28, December 2015, page 1863; Mineralogical Magazine: 79: 1859–1864; Oberti, R., Boiocchi, M., Hawthorne, F.C., Ball, N.A., Blass, G. (2017): Ferri-obertiite from the Rothenberg quarry, Eifel volcanic complex (Germany): mineral data and crystal-chemistry of a new amphibole end-member. Mineralogical Magazine, 81, 641–651. |
| Blass, G., Graf, H.W., Kolitsch, U., Neue Funde aus der Vulkaneifel - ein Rückblick auf die Sammelsaison 2002, Mineralien-Welt 13/5, 2003 |
| New minerals approved by IMA CNMNC in August-September 2014 - Blass, G., Graf, HW., Kolitsch, U., Sebold, D., Über neue Mineralfunde aus der Vulkaneifel, MW 6/2005 |
Caspar quarry, Bellerberg volcano, Ettringen, Mayen, Rhineland-Palatinate, Germany