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

Ishikawaite from
Penfield Quarry (Oak Leaf Quarry), Portland, Middlesex County, Connecticut, USA


04830710017402875601567.jpg
Ishikawaite, etc.

Penfield Quarry, Portland, Middlesex County, Connecticut, USA
03195250017401989814281.jpg
Ishikawaite, etc.

Penfield Quarry, Portland, Middlesex County, Connecticut, USA
06365120017272014902314.jpg
Ishikawaite, etc.

Penfield Quarry, Portland, Middlesex County, Connecticut, USA
09124250017402875603745.jpg
Ishikawaite, etc.

Penfield Quarry, Portland, Middlesex County, Connecticut, USA
03346690017401988421719.jpg
Ishikawaite, etc.

Penfield Quarry, Portland, Middlesex County, Connecticut, USA
03195250017401989814281.jpg
Ishikawaite, etc.

Penfield Quarry, Portland, Middlesex County, Connecticut, USA
06425900017272043932934.jpg
Ishikawaite, etc.

Penfield Quarry, Portland, Middlesex County, Connecticut, USA
01676090017401990823553.jpg
Ishikawaite, etc.

Penfield Quarry, Portland, Middlesex County, Connecticut, USA
03738090017402875617744.jpg
Ishikawaite, etc.

Penfield Quarry, Portland, Middlesex County, Connecticut, USA
06196680017402875618862.jpg
Ishikawaite, etc.

Penfield Quarry, Portland, Middlesex County, Connecticut, USA
06365120017272014902314.jpg
Ishikawaite, etc.

Penfield Quarry, Portland, Middlesex County, Connecticut, USA
08750370017402875617241.jpg
Ishikawaite, etc.

Penfield Quarry, Portland, Middlesex County, Connecticut, USA
Locality type:Quarry
Classification
Species:Ishikawaite
Formula:U4+Fe2+Nb2O8
Comments:metamict crystals with obsidian-like conchoidal fracture
Habit:tabular
Colour:black with brown coating
Quality for species:Good crystals or rich for species - important (!)
Confirmation
Validity:Believed Valid
Associated Minerals Based on Photo Data:
Quartz4
Columbite-(Fe)3
Albite1
Microcline1
Data
Mineral Data:Click here to view Ishikawaite data
Locality Data:Click here to view Penfield Quarry (Oak Leaf Quarry), Portland, Middlesex County, Connecticut, USA
Photo GalleryView Gallery (4 photos)
Data Identifiers
Mindat Occurrence Record ID:645148
Long-form Identifier:1:3:645148:6
GUID (UUID V4):0
Nearest other occurrences of Ishikawaite
9.8km (6.1 miles) ⓘSpinelli prospect (Spinelli quarry), Glastonbury, Hartford County, Connecticut, USA
References
Hanson, S. L., Jarnot, B. M., Falster, A. U., Simmons, W. B., Nizamoff, J. W. (2003) Nb-Ta-Ti oxide minerals from two pegmatites of the Middletown area, Connecticut. Rochester Mineralogical Symposium Abstracts, 11-12.
 
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 07:59:19
Go to top of page