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
Castanheira, Albergaria da Serra, Cabreiros e Albergaria da Serra, Arouca, Aveiro, Portugal


08542690017653036145059.jpg
Biotite

Castanheira, Albergaria da Serra, Cabreiros e Albergaria da Serra, Arouca, Aveiro, Portugal
07833010017272037786548.jpg
Biotite

Castanheira, Albergaria da Serra, Cabreiros e Albergaria da Serra, Arouca, Aveiro, Portugal
09628630017272314097667.jpg
Biotite

Castanheira, Albergaria da Serra, Cabreiros e Albergaria da Serra, Arouca, Aveiro, Portugal
04544140017272314123134.jpg
Biotite

Castanheira, Albergaria da Serra, Cabreiros e Albergaria da Serra, Arouca, Aveiro, Portugal
09805550017653036099695.jpg
Biotite

Castanheira, Albergaria da Serra, Cabreiros e Albergaria da Serra, Arouca, Aveiro, Portugal
09773070017653090253791.jpg
Biotite

Castanheira, Albergaria da Serra, Cabreiros e Albergaria da Serra, Arouca, Aveiro, Portugal
09628630017272314097667.jpg
Biotite

Castanheira, Albergaria da Serra, Cabreiros e Albergaria da Serra, Arouca, Aveiro, Portugal
04544140017272314123134.jpg
Biotite

Castanheira, Albergaria da Serra, Cabreiros e Albergaria da Serra, Arouca, Aveiro, Portugal
01417210017653090261948.jpg
Biotite

Castanheira, Albergaria da Serra, Cabreiros e Albergaria da Serra, Arouca, Aveiro, Portugal
07833010017272037786548.jpg
Biotite

Castanheira, Albergaria da Serra, Cabreiros e Albergaria da Serra, Arouca, Aveiro, Portugal
09628630017272314097667.jpg
Biotite

Castanheira, Albergaria da Serra, Cabreiros e Albergaria da Serra, Arouca, Aveiro, Portugal
04544140017272314123134.jpg
Biotite

Castanheira, Albergaria da Serra, Cabreiros e Albergaria da Serra, Arouca, Aveiro, Portugal
Locality type:Outcrop
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:Confirmed
Confirmation Methods:Visually Identified
Data
Mineral Data:Click here to view Biotite data
Locality Data:Click here to view Castanheira, Albergaria da Serra, Cabreiros e Albergaria da Serra, Arouca, Aveiro, Portugal
Photo GalleryView Gallery (14 photos)
Data Identifiers
Mindat Occurrence Record ID:754062
Long-form Identifier:1:3:754062:2
GUID (UUID V4):0
Nearest other occurrences of Biotite
2.3km (1.4 miles) ⓘFreita Mountain, Albergaria da Serra, Arouca, Aveiro, Portugal
12.8km (8.0 miles) ⓘRegoufe Mines, Covelo de Paivó, Arouca, Aveiro, Portugal
25.9km (16.1 miles) ⓘBejanca Mine (Carvalhal do Estanho), Queirã, Vouzela, Viseu, Portugal
30.3km (18.9 miles) ⓘSeixos Alvos Mine, U.F Couto de Cima e Couto de Baixo, Viseu, Viseu, Portugal
46.9km (29.1 miles) ⓘPicoto Mine, Vilar Seco, Nelas, Viseu, Portugal
50.0km (31.0 miles) ⓘRegada, Cubos-Mesquitela-Mangualde area, Mangualde (Mesquitela e Cunha Alta), Mangualde, Viseu, Portugal
52.6km (32.7 miles) ⓘCubos-Mesquitela-Mangualde area, Mangualde (Mesquitela e Cunha Alta), Mangualde, Viseu, Portugal
53.6km (33.3 miles) ⓘChão do Castanheiro, Cubos-Mesquitela-Mangualde area, Mangualde (Mesquitela e Cunha Alta), Mangualde, Viseu, Portugal
53.6km (33.3 miles) ⓘRochel, Cubos-Mesquitela-Mangualde area, Mangualde (Mesquitela e Cunha Alta), Mangualde, Viseu, Portugal
55.0km (34.2 miles) ⓘAssunção Mine, Aldeia Nova, Ferreira de Aves, Sátão, Viseu, Portugal
References
According to pioneer work carried out in the 1950s by C.T Assunção & C.Teixeira (Boletim do Museu e Laboratório Mineralógico e Geológico Faculdadede Ciências, 1954, v.27, pp.7–17).
Rui Nunes October 2011.
 
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