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
Venturinha, Sezures, Penalva do Castelo, Viseu, Portugal


Locality type:Open-Cast 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 Venturinha, Sezures, Penalva do Castelo, Viseu, Portugal
Data Identifiers
Mindat Occurrence Record ID:159349
Long-form Identifier:1:3:159349:5
GUID (UUID V4):0
Nearest other occurrences of Biotite
6.6km (4.1 miles) ⓘFonte Limeira quarry, U.F Romãs Decermilo e Vila Longa, Sátão, Viseu, Portugal
9.5km (5.9 miles) ⓘVila Seca Mine, Vila Seca, Tavares (Chãs; Várzea e Travanca), Mangualde, Viseu, Portugal
12.2km (7.6 miles) ⓘAssunção Mine, Aldeia Nova, Ferreira de Aves, Sátão, Viseu, Portugal
13.2km (8.2 miles) ⓘVigia Mine, U.F. Aguiar da Beira e Coruche, Aguiar da Beira, Guarda, Portugal
14.2km (8.8 miles) ⓘRegada, Cubos-Mesquitela-Mangualde area, Mangualde (Mesquitela e Cunha Alta), Mangualde, Viseu, Portugal
16.3km (10.1 miles) ⓘRochel, Cubos-Mesquitela-Mangualde area, Mangualde (Mesquitela e Cunha Alta), Mangualde, Viseu, Portugal
16.4km (10.2 miles) ⓘChão do Castanheiro, Cubos-Mesquitela-Mangualde area, Mangualde (Mesquitela e Cunha Alta), Mangualde, Viseu, Portugal
16.6km (10.3 miles) ⓘRatoeira quarry, U.F. Sequeiros e Gradiz, Aguiar da Beira, Guarda, Portugal
16.9km (10.5 miles) ⓘCubos-Mesquitela-Mangualde area, Mangualde (Mesquitela e Cunha Alta), Mangualde, Viseu, Portugal
17.3km (10.7 miles) ⓘRatoeira No. 1 quarry, U.F. Sequeiros e Gradiz, Aguiar da Beira, Guarda, Portugal
References
Correia Neves, J.M. (1962), Pegmatito da Região da Venturinha (Penalva do Castelo, Viseu), Memórias e Noticias do Museu e Laboratório Mineralógico e Geológico da Universidade de Coimbra, vol. 54, 1962: 1-135.
 
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