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!
Log InRegister
Quick Links : The Mindat ManualThe Rock H. Currier Digital LibraryMindat Newsletter [Free Download]
Home PageAbout MindatThe Mindat ManualHistory of MindatCopyright StatusWho We AreContact UsAdvertise on Mindat
Donate to MindatCorporate SponsorshipSponsor a PageSponsored PagesMindat AdvertisersAdvertise on Mindat
Learning CenterWhat is a mineral?The most common minerals on earthInformation for EducatorsMindat ArticlesThe ElementsThe Rock H. Currier Digital LibraryGeologic TimeExplore Fossils
Minerals by PropertiesMinerals by ChemistryMineral Visual ExplorerAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
Mining CompaniesStatisticsUsersMineral MuseumsClubs & OrganizationsMineral Shows & EventsThe Mindat DirectoryDevice SettingsThe Mineral QuizTime Machine
Photo SearchPhoto GalleriesSearch by ColorPhoto Colour ExplorerNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryPhotography

Biotite from
Masons Island Quarry, Stonington, New London County, Connecticut, USA


Locality type:Quarry
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 Masons Island Quarry, Stonington, New London County, Connecticut, USA
Data Identifiers
Mindat Occurrence Record ID:720300
Long-form Identifier:1:3:720300:8
GUID (UUID V4):0
Nearest other occurrences of Biotite
13.4km (8.3 miles) ⓘSmith Granite quarry, Westerly, Washington County, Rhode Island, USA
13.5km (8.4 miles) ⓘWhite Rock Quarry, Westerly, Washington County, Rhode Island, USA
14.7km (9.1 miles) ⓘRedstone Granite Quarry (Cherenzia Quarry), Westerly, Washington County, Rhode Island, USA
29.9km (18.6 miles) ⓘMacCurdy Quarry, Old Lyme, New London County, Connecticut, USA
38.5km (23.9 miles) ⓘWest Kingston, South Kingstown, Washington County, Rhode Island, USA
40.5km (25.2 miles) ⓘKingston Hill, South Kingstown, Washington County, Rhode Island, USA
40.9km (25.4 miles) ⓘHaynes Deep River Quarry, Deep River, Middlesex County, Connecticut, USA
42.6km (26.5 miles) ⓘMooresfield Granite quarry, South Kingstown, Washington County, Rhode Island, USA
44.7km (27.8 miles) ⓘTower Hill, Narragansett, Washington County, Rhode Island, USA
47.0km (29.2 miles) ⓘArnold Granite Quarry (General Brainerd Quarry; Great Hill Quarry; Hazelton Quarry; Haddam Quarry; Brookes Quarry), Haddam, Middlesex County, Connecticut, USA
References
Dale, T. Nelson; Gregory Herbert E. (1911) The granites of Connecticut. Bulletin 484. US Geological Survey doi:10.3133/b484
 
and/or  
Mindat.org® is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Mindat® and mindat.org® are registered trademarks of the Hudson Institute of Mineralogy.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2026, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 by Jolyon Ralph and Ida Chau.
Content on this site may not be used to train, fine-tune, or otherwise develop artificial intelligence or machine learning models without prior written permission - see our Terms & Conditions.
To cite: Ralph, J., Von Bargen, D., Martynov, P., Zhang, J., Que, X., Prabhu, A., Morrison, S. M., Li, W., Chen, W., & Ma, X. (2025). Mindat.org: The open access mineralogy database to accelerate data-intensive geoscience research. American Mineralogist, 110(6), 833–844. doi:10.2138/am-2024-9486.
Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: September 3, 2026 15:14:36
Go to top of page