Log InRegister
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 Articles
Minerals by PropertiesMinerals by ChemistryAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
Mining CompaniesStatisticsThe ElementsUsersBooks & MagazinesMineral MuseumsMineral Shows & EventsThe Mindat DirectoryDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery

Lantern Hill Quarry (Silex Quarry; U.S. Silica Company Quarry), North Stonington, New London Co., Connecticut, USAi
Regional Level Types
Lantern Hill Quarry (Silex Quarry; U.S. Silica Company Quarry)Quarry
North Stonington- not defined -
New London Co.County

This page is currently not sponsored. Click here to sponsor this page.
Lock Map
Latitude & Longitude (WGS84): 41° 27' 20'' North , 71° 56' 41'' West
Latitude & Longitude (decimal): 41.45556,-71.94472
GeoHash:G#: drkgffg2n
Locality type:Quarry
Köppen climate type:Cfb : Temperate oceanic climate
Nearest Settlements:
Mashantucket299 (2017)2.9km
Ledyard15,212 (2017)6.0km
Old Mystic3,554 (2017)7.3km
Preston City5,000 (2017)8.5km
Mystic4,205 (2017)11.4km

A former quartz mine, opened in 1870s, in a 1.6-km-long and 71m thick quartz lode that also underlies Lantern Hill to the north of the quarry. Since 1994, the land has been owned by the Mashantucket Pequot Tribal Nation. According to Altamura (1995), high-purity silica from here was used for glass making, foundry sand, aquarium sand, swimming pool filters, sandbox sand and architectural aggregate - such as on the concrete faces of the J. F. Kennedy presidential library near Boston. The hydrothermal quartz deposit occurred along rift faults 238 Ma (from primary muscovite, early middle Triassic), 19 Ma before sedimentation in the Triassic-Jurassic Hartford Basin began.

Small quartz crystals can be found in talus along cliffs on 120 m high Lantern Hill.

Regions containing this locality

North America PlateTectonic Plate

Select Mineral List Type

Standard Detailed Strunz Dana Chemical Elements

Mineral List

3 valid minerals.

Detailed Mineral List:

Formula: Al2(Si2O5)(OH)4
Formula: PbAl3(PO4)(PO3OH)(OH)6
Formula: SiO2

List of minerals arranged by Strunz 10th Edition classification

Group 4 - Oxides and Hydroxides
Group 8 - Phosphates, Arsenates and Vanadates
Group 9 - Silicates

List of minerals arranged by Dana 8th Edition classification

Group 75 - TECTOSILICATES Si Tetrahedral Frameworks
Si Tetrahedral Frameworks - SiO2 with [4] coordinated Si
Unclassified Minerals, Mixtures, etc.

List of minerals for each chemical element

H PlumbogummitePbAl3(PO4)(PO3OH)(OH)6
H KaoliniteAl2(Si2O5)(OH)4
O QuartzSiO2
O PlumbogummitePbAl3(PO4)(PO3OH)(OH)6
O KaoliniteAl2(Si2O5)(OH)4
Al PlumbogummitePbAl3(PO4)(PO3OH)(OH)6
Al KaoliniteAl2(Si2O5)(OH)4
Si QuartzSiO2
Si KaoliniteAl2(Si2O5)(OH)4
P PlumbogummitePbAl3(PO4)(PO3OH)(OH)6
Pb PlumbogummitePbAl3(PO4)(PO3OH)(OH)6

Regional Geology

This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.

Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org

145 - 201.3 Ma

ID: 2750152
Silicified rock and mylonite along Mesozoic faults

Age: Jurassic (145 - 201.3 Ma)

Description: Close network of quartz veins and veinlets cutting each other and older rock, which is mostly replaced by very fine grained quartz. In places, incompletely replaced rock shows strongly mylonitic texture.

Comments: Part of Eastern Uplands; Fault-related rocks Original map source: Connecticut Geological and Natural History Survey, DEP, in cooperation with the U.S. Geological Survey, 2000, Bedrock Geology of Connecticut, shapefile, scale 1:50,000

Lithology: Major:{mylonite}

Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052. [133]

Devonian - Silurian
358.9 - 443.8 Ma

ID: 3186140
Paleozoic sedimentary and volcanic rocks

Age: Paleozoic (358.9 - 443.8 Ma)

Lithology: Mudstone-carbonate-sandstone-conglomerate

Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529. [154]

Data and map coding provided by Macrostrat.org, used under Creative Commons Attribution 4.0 License


Sort by

Year (asc) Year (desc) Author (A-Z) Author (Z-A)
Ryerson, Kathleen H. (1972), Rock Hound's Guide to Connecticut. Pequot Press.
Altamura, Robert J. (1995), Tectonics, Wall-Rock Alteration and Emplacement History of the Lantern Hill Giant Quartz Lode, Avalonian Terrane, Southeastern Connecticut. Trip E in Guidebook for Fieldtrips in Eastern Connecticut and the Hartford Basin. Northeast Section Geological Society of America 30th Annual Meeting. State Geological and Natural History Survey of Connecticut Guidebook No. 7.
Weber, Marcelle H. and Earle C. Sullivan. (1995): Connecticut Mineral Locality Index. Rocks & Minerals (Connecticut Issue): 70(6): 407.
Pawloski, John A. (2006), Connecticut Mining. Arcadia Publishing, Mt. Pleasant, SC.

This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.
Mineral and/or Locality  
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Public Relations by Blytheweigh.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2019, except where stated. Mindat.org relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: February 21, 2019 16:00:46 Page generated: January 11, 2019 01:30:42
Go to top of page