Vote for your favorite mineral in #MinCup26! - Sphalerite vs. Anorthite
Both zinc ore Sphalerite and calcium plagioclase feldspar Anorthite have perfect cleavage that will split cleanly if you hit them with a hammer, but only one can claim a larger split of your votes!
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Biotite from
Tre Croci, Vetralla, Viterbo Province, Lazio, Italy


07690320017367053925567.jpg
Biotite

Tre Croci, Vetralla, Viterbo Province, Lazio, Italy
05125610017272001298769.jpg
Biotite

Tre Croci, Vetralla, Viterbo Province, Lazio, Italy
09320170017272722855481.jpg
Phlogopite, etc.

Tre Croci, Vetralla, Viterbo Province, Lazio, Italy
00118620017367883408409.jpg
Biotite

Tre Croci, Vetralla, Viterbo Province, Lazio, Italy
05125610017272001298769.jpg
Biotite

Tre Croci, Vetralla, Viterbo Province, Lazio, Italy
03858540017272002501328.jpg
Phlogopite, etc.

Tre Croci, Vetralla, Viterbo Province, Lazio, Italy
07690320017367053925567.jpg
Biotite

Tre Croci, Vetralla, Viterbo Province, Lazio, Italy
05125610017272001298769.jpg
Biotite

Tre Croci, Vetralla, Viterbo Province, Lazio, Italy
03858540017272002501328.jpg
Phlogopite, etc.

Tre Croci, Vetralla, Viterbo Province, Lazio, Italy
Locality type:Village
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
Associated Minerals Based on Photo Data:
Baddeleyite2
Hellandite Group2
Vonsenite2
Hornblende Root Name Group1
Ciprianiite1
Sanidine1
Tadzhikite-(Ce)1
Data
Mineral Data:Click here to view Biotite data
Locality Data:Click here to view Tre Croci, Vetralla, Viterbo Province, Lazio, Italy
Photo GalleryView Gallery (2 photos)
Data Identifiers
Mindat Occurrence Record ID:617708
Long-form Identifier:1:3:617708:9
GUID (UUID V4):0
Nearest other occurrences of Biotite
2.2km (1.4 miles) ⓘLe Carcarelle, Viterbo, Viterbo Province, Lazio, Italy
5.7km (3.6 miles) ⓘSan Martino al Cimino, Viterbo, Viterbo Province, Lazio, Italy
21.0km (13.0 miles) ⓘSH2 deep well, Bracciano, Metropolitan City of Rome Capital, Lazio, Italy
23.8km (14.8 miles) ⓘMonte Rovello, Allumiere, Metropolitan City of Rome Capital, Lazio, Italy
26.9km (16.7 miles) ⓘSpizzicatore Hill, Allumiere, Metropolitan City of Rome Capital, Lazio, Italy
29.0km (18.1 miles) ⓘPianciano, Castel Giuliano, Bracciano, Metropolitan City of Rome Capital, Lazio, Italy
31.6km (19.7 miles) ⓘLa Mola, Anguillara Sabazia, Metropolitan City of Rome Capital, Lazio, Italy
31.9km (19.8 miles) ⓘTrachyte quarry, Ponzano, Bagnoregio, Viterbo Province, Lazio, Italy
35.1km (21.8 miles) ⓘMonte Cavalluccio, Campagnano di Roma, Metropolitan City of Rome Capital, Lazio, Italy
35.7km (22.2 miles) ⓘFosso Attici, Magliano Romano, Metropolitan City of Rome Capital, Lazio, Italy
References
Boiocchi, M. (2006) The crystal structure of piergorite-(Ce), Ca8Ce2(Al0.5 Fe0.53+)Σ1([],Li,Be)2Si6B8O36(OH,F)2: A new borosilicate from Vetralla, Italy, with a modified hellandite-type chain. American Mineralogist, 91 (7). 1170-1177 doi:10.2138/am.2006.2139
 
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