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Betafite Group

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Formula:
A2(Ti,Nb)2O6Z
A is primarily Ca or U4+ but can also be Na, Sn2+, Sr, Pb2+, Sb3+, Y, H2O or ◻.

Z is primarily O, but can also be OH, F, H2O or ◻
Name:
Betafite the species, was named in 1912 by Antoine François Alfred Lacroix for the "type" locality. Betafite was redefined in 1961, by Donald D. Hogarth and, betafite remained a species, but frequently with "anomalous" chemistry. Lumpkin and Ewing (1996) studied nine specimens historically labeled "betafite" and discovered that replacement and alteration was present in their samples. Titanium-rich minerals intergrown with pyrochlore super group crystals gave a false impression of the bulk chemistry of specimens. Atencio, et al. (2010)reported on the IMA-approved supergroup nomenclature and Christy and Atencio (2013) added corrections to the IMA report.

The result of modern pinpoint analyses is that almost all specimens formerly labeled betafite are no longer members of that group/series. New analyses, including determination of H2O, OH, and F are necessary to identify the species of a particular sample. The root-name, betafite, was retained for historical reasons.
The nomenclature was recently revised by Atencio et al. (2010); see also Christy & Atencio (2013). The reason "betafite group" species are so scarce when they previously seemed to be widespread is that many erstwhile "betafite group" specimens, particularly large crystals from Madagascar, were partially intergrown with rutile and several rare titanium-rich species. Chemical analyses of bulk specimens showed an erroneously high titanium content due to inclusions.

Classification of Betafite Group

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Chemical Properties of Betafite Group

Formula:
A2(Ti,Nb)2O6Z

A is primarily Ca or U4+ but can also be Na, Sn2+, Sr, Pb2+, Sb3+, Y, H2O or ◻.

Z is primarily O, but can also be OH, F, H2O or ◻

Relationship of Betafite Group to other Species

Group Members:
Oxycalciobetafite Ca2(Ti,Nb)2O6O
Oxyuranobetafite (U,Ca,◻)2(Ti,Nb)2O6O

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 Betafite Group

Reference List:
Hogarth, Donald D.(1961): A Study of Pyrochlore and Betafite. Canadian Mineralogist. 6: 610-633.

Lumpkin, Gregory R. and Ewing, Rodney C.(1996) : Geochemical alteration of pyrochlore group minerals: Betafite subgroup. American Mineralogist. 81: 1237-1248.

Atencio Daniel, Andrade M. B., Christy A. G., Giere R., Kartashov Pavel M. (2010): The pyrochlore supergroup of minerals: nomenclature. Canadian Mineralogist. 48: 673-698.

Christy, A. G. and Atencio, Daniel (2013): Clarification of status of species in the pyrochlore supergroup. Mineralogical Magazine. 77: 13-20.

Internet Links for Betafite Group

Specimens:
The following Betafite Group specimens are currently listed for sale on minfind.com.

Localities for Betafite Group

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.
Mineral and/or Locality  
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