Vote for your favorite mineral in #MinCup26! - Quartz vs. Asagiite
It's a classic vs a newbie as the most common named mineral in the crust Quartz is up against an exceedingly-rare sea foam-green mineral discovered just a few years ago Asagiite.
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Biotite from
Cevadais occurrence, Campo Maior, Portalegre, Portugal


Locality type:Occurrence
Classification
Species:'Biotite' (not an IMA approved species)
Formula:K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Confirmation
Validity:Believed Valid
Data
Mineral Data:Click here to view Biotite data
Locality Data:Click here to view Cevadais occurrence, Campo Maior, Portalegre, Portugal
Data Identifiers
Mindat Occurrence Record ID:1408602
Long-form Identifier:1:3:1408602:5
GUID (UUID V4):0
Nearest other occurrences of Biotite
34.1km (21.2 miles) ⓘD. João quarry (Herdade do Padre João), Monforte, Monforte, Portalegre, Portugal
45.9km (28.5 miles) ⓘSierra de San Pedro, Cáceres, Cáceres, Extremadura, Spain
47.4km (29.4 miles) ⓘCabeço de Vide ultramafic complex, Alter do Chão, Portalegre, Portugal
83.3km (51.7 miles) ⓘSegura Mines (Segura mining field), União das Freguesias de Zebreira e Segura, Idanha-a-Nova, Castelo Branco, Portugal
83.4km (51.8 miles) ⓘCerro Queimado, União das Freguesias de Zebreira e Segura, Idanha-a-Nova, Castelo Branco, Portugal
References
Assunção, C.T. and Gonçalves, F. (1971) Contribuição para o conhecimento das rochas hiperalcalinas e alcalinas (gnaisses hastingsíticos) do Alto Alentejo (Portugal). Bolletim da Sociedade Geológica de Portuga, 17, 187-229.
Teixeira, C., & de Assunção, C. T. (1958). Sur la géologie et la pétrographie des gneiss à riebeckite et aegyrine et des syénites à néphéline et sodalite de Cevadais, prés d'Ouguela (Campo Maior), Portugal. Cominicações dos Serviços Geológicos de Portugal, 42, 31-56.
 
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