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

Tourmaline from
Hunting Hill Quarry, Rockville, Montgomery County, Maryland, USA


05156150017362077216550.jpg
Tourmaline

Hunting Hill Quarry, Rockville, Montgomery County, Maryland, USA
00175670017362077224313.jpg
Tourmaline

Hunting Hill Quarry, Rockville, Montgomery County, Maryland, USA
05156150017362077216550.jpg
Tourmaline

Hunting Hill Quarry, Rockville, Montgomery County, Maryland, USA
00175670017362077224313.jpg
Tourmaline

Hunting Hill Quarry, Rockville, Montgomery County, Maryland, USA
05156150017362077216550.jpg
Tourmaline

Hunting Hill Quarry, Rockville, Montgomery County, Maryland, USA
00175670017362077224313.jpg
Tourmaline

Hunting Hill Quarry, Rockville, Montgomery County, Maryland, USA
Locality type:Quarry
Classification
Species:'Tourmaline' (not an IMA approved species)
Formula:AD3G6(T6O18)(BO3)3X3Z
Confirmation
Validity:Believed Valid
Data
Mineral Data:Click here to view Tourmaline data
Locality Data:Click here to view Hunting Hill Quarry, Rockville, Montgomery County, Maryland, USA
Data Identifiers
Mindat Occurrence Record ID:46618
Long-form Identifier:1:3:46618:1
GUID (UUID V4):0
Nearest other occurrences of Tourmaline
11.4km (7.1 miles) ⓘDifficult Run, Fairfax County, Virginia, USA
20.6km (12.8 miles) ⓘEtchison Mine, Montgomery County, Maryland, USA
36.3km (22.6 miles) ⓘBull Run Quarry, Conklin, Loudoun County, Virginia, USA
38.4km (23.8 miles) ⓘNew London Mine (Linganore Mine), New London, Frederick County, Maryland, USA
43.1km (26.8 miles) ⓘVulcan Materials Company Crushed Stone Quarry (Manassas Quarry), Manassas, Prince William County, Virginia, USA
57.0km (35.4 miles) ⓘCabin Branch Mine (Dumfries Mine), Dumfries, Gold-Pyrite Belt, Prince William County, Virginia, USA
74.3km (46.2 miles) ⓘFranklin Mine (Deep Run Mine), Midland, Gold-Pyrite Belt, Fauquier County, Virginia, USA
81.2km (50.4 miles) ⓘManassas Gap Mine, Northern Section-Blue Ridge Province, Fauquier County, Virginia, USA
86.0km (53.4 miles) ⓘEagle Mine (Morgan and Rappahannock; Smith), Gold-Pyrite Belt, Stafford County, Virginia, USA
87.7km (54.5 miles) ⓘScientists Cliffs beach alluvials, Calvert County, Maryland, USA
References
Bernstein, Lawrence R. (1980) Minerals of the Washington, D.C. Area - Issue 5 of Educational series, Maryland Geological Survey. Department of Natural Resources, Maryland Geological Survey. p.1-148.
 
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 08:50:44
Go to top of page