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

Montmorillonite from
Walden Gem Quarry, Portland, Middlesex County, Connecticut, USA


Locality type:Quarry
Classification
Species:Montmorillonite
Formula:(Na,Ca)0.33(Al,Mg)2(Si4O10)(OH)2 · nH2O
Confirmation
Validity:Believed Valid
Data
Mineral Data:Click here to view Montmorillonite data
Locality Data:Click here to view Walden Gem Quarry, Portland, Middlesex County, Connecticut, USA
Data Identifiers
Mindat Occurrence Record ID:657258
Long-form Identifier:1:3:657258:7
GUID (UUID V4):0
Nearest other occurrences of Montmorillonite
1.2km (0.7 miles) ⓘHale Quarry (Andrews Quarry; Glastonbury Quarry), Portland, Middlesex County, Connecticut, USA
1.4km (0.9 miles) ⓘAndrews Quarry (old Hale Quarry; Grandfather Andrews Quarry), Portland, Middlesex County, Connecticut, USA
3.0km (1.8 miles) ⓘStrickland Quarry, Strickland pegmatite, Collins Hill, Portland, Middlesex County, Connecticut, USA
15.7km (9.8 miles) ⓘGillette Quarry (J-J Mine; Haddam Neck Quarry), Haddam Neck, Haddam, Middlesex County, Connecticut, USA
40.2km (25.0 miles) ⓘThomaston Dam railroad cut, Thomaston Dam, Thomaston, Litchfield County, Connecticut, USA
68.6km (42.6 miles) ⓘBlandford mica mines, Blandford, Hampden County, Massachusetts, USA
71.2km (44.2 miles) ⓘKent Iron Mine (Limonite mine), Kent, Litchfield County, Connecticut, USA
71.2km (44.2 miles) ⓘDiamond Hill (Ashaway Village), Ashaway, Hopkinton, Washington County, Rhode Island, USA
74.5km (46.3 miles) ⓘLoudville Lead Mines (Manhan Lead-Silver Mine; Southampton Lead Mine; Northampton Lead Mine), Easthampton, Hampshire County, Massachusetts, USA
80.4km (50.0 miles) ⓘFillow Quarry, Branchville, Redding, Fairfield County, Connecticut, USA
References
Rocks & Minerals (1970) 45:595-600
 
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 10:26:10
Go to top of page