Vote for your favorite mineral in #MinCup26! - Cuprite vs. Orpiment
It's a fiery match of vibrant red Cuprite and just as saturated orange Orpiment battle for 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

Prehnite from
Keystone Bay/Point, Grant Township, Keweenaw County, Michigan, USA


04036740017362086897547.jpg
Prehnite

Keystone Bay/Point, Grant Township, Keweenaw County, Michigan, USA
04036740017362086897547.jpg
Prehnite

Keystone Bay/Point, Grant Township, Keweenaw County, Michigan, USA
06458310017272422865947.jpg
Prehnite

Keystone Bay/Point, Grant Township, Keweenaw County, Michigan, USA
Locality type:Outcrop
Classification
Species:Prehnite
Formula:Ca2Al2Si3O10(OH)2
Confirmation
Validity:Confirmed
Confirmation Methods:Visually Identified
Data
Mineral Data:Click here to view Prehnite data
Locality Data:Click here to view Keystone Bay/Point, Grant Township, Keweenaw County, Michigan, USA
Data Identifiers
Mindat Occurrence Record ID:1475151
Long-form Identifier:1:3:1475151:8
GUID (UUID V4):0
Nearest other occurrences of Prehnite
2.0km (1.2 miles) ⓘPoint Prospect, Grant Township, Keweenaw County, Michigan, USA
3.9km (2.4 miles) ⓘVulcan Exploration Copper Mine, Grant Township, Keweenaw County, Michigan, USA
4.1km (2.6 miles) ⓘLac La Belle exploration, Lac La Belle, Grant Township, Keweenaw County, Michigan, USA
5.3km (3.3 miles) ⓘNew York and Michigan Exploration, Grant Township, Keweenaw County, Michigan, USA
8.7km (5.4 miles) ⓘCape Mine, Mosquito Mining District, Copper Harbor, Grant Township, Keweenaw County, Michigan, USA
8.7km (5.4 miles) ⓘStar Mine, Copper Harbor, Grant Township, Keweenaw County, Michigan, USA
9.1km (5.6 miles) ⓘClark Mine, Copper Harbor, Grant Township, Keweenaw County, Michigan, USA
9.9km (6.2 miles) ⓘManganese Mine, Copper Harbor, Grant Township, Keweenaw County, Michigan, USA
12.3km (7.6 miles) ⓘCopper Harbor, Grant Township, Keweenaw County, Michigan, USA
13.3km (8.3 miles) ⓘAetna Exploration Copper Mine, Grant Township, Keweenaw County, Michigan, USA
References
Allan Blaske collection
 
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 5, 2026 00:24:43
Go to top of page