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
Trelavour Downs, St Dennis, Cornwall, England, UK


03354630017271997505444.jpg
Biotite

Trelavour Downs, St Dennis, Cornwall, England, UK
04645950017362784775408.jpg
Biotite

Trelavour Downs, St Dennis, Cornwall, England, UK
03647360017271997539162.jpg
Biotite

Trelavour Downs, St Dennis, Cornwall, England, UK
03812310017427438568420.jpg
Biotite

Trelavour Downs, St Dennis, Cornwall, England, UK
03354630017271997505444.jpg
Biotite

Trelavour Downs, St Dennis, Cornwall, England, UK
04645950017362784775408.jpg
Biotite

Trelavour Downs, St Dennis, Cornwall, England, UK
03647360017271997539162.jpg
Biotite

Trelavour Downs, St Dennis, Cornwall, England, UK
08579220017427437616405.jpg
Biotite

Trelavour Downs, St Dennis, Cornwall, England, UK
03354630017271997505444.jpg
Biotite

Trelavour Downs, St Dennis, Cornwall, England, UK
04645950017362784775408.jpg
Biotite

Trelavour Downs, St Dennis, Cornwall, England, UK
03647360017271997539162.jpg
Biotite

Trelavour Downs, St Dennis, Cornwall, England, UK
04738120017427598643703.jpg
Biotite

Trelavour Downs, St Dennis, Cornwall, England, UK
Locality type:Downs
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 Trelavour Downs, St Dennis, Cornwall, England, UK
Photo GalleryView Gallery (3 photos)
Data Identifiers
Mindat Occurrence Record ID:1999
Long-form Identifier:1:3:1999:6
GUID (UUID V4):0
Nearest other occurrences of Biotite
4.4km (2.7 miles) ⓘGunheath China Clay Pit, Stenalees, Treverbyn, Cornwall, England, UK
4.7km (2.9 miles) ⓘDyer's Quarry, Chytane, St Enoder, Cornwall, England, UK
9.2km (5.7 miles) ⓘBodelva Pit (Carvear China Clay Works), Bodelva, St Blaise, Cornwall, England, UK
28.8km (17.9 miles) ⓘLushington Cove, Porthtowan, St Agnes, Cornwall, England, UK
29.1km (18.1 miles) ⓘPendennis Head, Falmouth, Cornwall, England, UK
32.4km (20.1 miles) ⓘCraddock Moor Mine, Craddock Moor, St Cleer, Cornwall, England, UK
33.2km (20.6 miles) ⓘSouth Caradon Mine, Caradon Hill, St Cleer, Cornwall, England, UK
33.2km (20.6 miles) ⓘCheesewring Quarry, Minions, Linkinhorne, Cornwall, England, UK
33.8km (21.0 miles) ⓘSouth Crofty Mine, Pool, Carn Brea, Cornwall, England, UK
34.6km (21.5 miles) ⓘEast Wheal Grenville, Grenville United Mines, Troon, Camborne, Cornwall, England, UK
References
Golley, Peter, Williams, Richard (1995) Cornish Mineral Reference Manual. Endsleigh Book Co., Truro. 71pp.
 
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