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
Vila Seca Mine, Vila Seca, Tavares (Chãs; Várzea e Travanca), Mangualde, Viseu, Portugal


Locality type:Mine
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 Vila Seca Mine, Vila Seca, Tavares (Chãs; Várzea e Travanca), Mangualde, Viseu, Portugal
Data Identifiers
Mindat Occurrence Record ID:487717
Long-form Identifier:1:3:487717:2
GUID (UUID V4):0
Nearest other occurrences of Biotite
9.5km (5.9 miles) ⓘVenturinha, Sezures, Penalva do Castelo, Viseu, Portugal
12.9km (8.0 miles) ⓘRochel, Cubos-Mesquitela-Mangualde area, Mangualde (Mesquitela e Cunha Alta), Mangualde, Viseu, Portugal
13.0km (8.1 miles) ⓘChão do Castanheiro, Cubos-Mesquitela-Mangualde area, Mangualde (Mesquitela e Cunha Alta), Mangualde, Viseu, Portugal
13.6km (8.5 miles) ⓘRegada, Cubos-Mesquitela-Mangualde area, Mangualde (Mesquitela e Cunha Alta), Mangualde, Viseu, Portugal
14.0km (8.7 miles) ⓘCubos-Mesquitela-Mangualde area, Mangualde (Mesquitela e Cunha Alta), Mangualde, Viseu, Portugal
14.8km (9.2 miles) ⓘFonte Limeira quarry, U.F Romãs Decermilo e Vila Longa, Sátão, Viseu, Portugal
20.9km (13.0 miles) ⓘAssunção Mine, Aldeia Nova, Ferreira de Aves, Sátão, Viseu, Portugal
21.0km (13.1 miles) ⓘVigia Mine, U.F. Aguiar da Beira e Coruche, Aguiar da Beira, Guarda, Portugal
23.1km (14.3 miles) ⓘPicoto Mine, Vilar Seco, Nelas, Viseu, Portugal
24.3km (15.1 miles) ⓘRatoeira quarry, U.F. Sequeiros e Gradiz, Aguiar da Beira, Guarda, Portugal
References
Nuno Afonso collection
 
and/or  
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