SUPPORT US. If is important to you, click here to donate to our Fall 2019 fundraiser!
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 ArticlesThe ElementsBooks & Magazines
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 CompaniesStatisticsUsersMineral MuseumsMineral Shows & EventsThe Mindat DirectoryDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryMineral Photography

Vivianite Concretion Locality, Riva, Anne Arundel Co., Maryland, USAi
Regional Level Types
Vivianite Concretion Locality- not defined -
Riva- not defined -
Anne Arundel Co.County

This page is currently not sponsored. Click here to sponsor this page.
Lock Map
Latitude & Longitude (WGS84): 38° 57' 58'' North , 76° 38' 2'' West
Latitude & Longitude (decimal): 38.96611,-76.63389
GeoHash:G#: dqct8jsfh
Köppen climate type:Cfa : Humid subtropical climate
Nearest Settlements:
Davidsonville8,000 (2013)4.8km
Riva4,076 (2011)5.1km
Crofton27,348 (2011)6.1km
Edgewater9,023 (2011)7.3km
Crownsville1,757 (2011)7.5km

Road cut along Tarnans Branch of the South River near the south bluff on Tarnans Branch, near the Rutland School Road Underpass of the expressway. Phosphate concretions to 20 cm in diameter were found about 1950. The vivianite either displays several different colors or there are several phosphates species present.

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: (K,Na)(Mg,Fe2+,Fe3+)(Fe3+,Al)(Si,Al)4O10(OH)2
Reference: Barwick, Authur R. (1951) Vivianite Concretions in Aquia Formation (Middle Eocene), Anne Arundel County, Maryland, American Mineralogist, 36: 629--630.
Formula: α-Fe3+O(OH)
Reference: Barwick, Authur R. (1951) Vivianite Concretions in Aquia Formation (Middle Eocene), Anne Arundel County, Maryland, American Mineralogist, 36: 629--630.
Formula: (Fe,O,OH,H2O)
Reference: Barwick, Authur R. (1951) Vivianite Concretions in Aquia Formation (Middle Eocene), Anne Arundel County, Maryland, American Mineralogist, 36: 629--630.
Formula: Fe2+3(PO4)2 · 8H2O
Reference: Barwick, Authur R. (1951) Vivianite Concretions in Aquia Formation (Middle Eocene), Anne Arundel County, Maryland, American Mineralogist, 36: 629--630.

List of minerals arranged by Strunz 10th Edition classification

Group 4 - Oxides and Hydroxides
Group 8 - Phosphates, Arsenates and Vanadates
Vivianite8.CE.40Fe2+3(PO4)2 · 8H2O
Unclassified Minerals, Rocks, etc.

List of minerals arranged by Dana 8th Edition classification

Vivianite40.3.6.1Fe2+3(PO4)2 · 8H2O
Group 71 - PHYLLOSILICATES Sheets of Six-Membered Rings
Sheets of 6-membered rings with 2:1 layers
Unclassified Minerals, Mixtures, etc.

List of minerals for each chemical element

H Goethiteα-Fe3+O(OH)
H Glauconite(K,Na)(Mg,Fe2+,Fe3+)(Fe3+,Al)(Si,Al)4O10(OH)2
H Limonite(Fe,O,OH,H2O)
H VivianiteFe32+(PO4)2 · 8H2O
O Goethiteα-Fe3+O(OH)
O Glauconite(K,Na)(Mg,Fe2+,Fe3+)(Fe3+,Al)(Si,Al)4O10(OH)2
O Limonite(Fe,O,OH,H2O)
O VivianiteFe32+(PO4)2 · 8H2O
Na Glauconite(K,Na)(Mg,Fe2+,Fe3+)(Fe3+,Al)(Si,Al)4O10(OH)2
Mg Glauconite(K,Na)(Mg,Fe2+,Fe3+)(Fe3+,Al)(Si,Al)4O10(OH)2
Al Glauconite(K,Na)(Mg,Fe2+,Fe3+)(Fe3+,Al)(Si,Al)4O10(OH)2
Si Glauconite(K,Na)(Mg,Fe2+,Fe3+)(Fe3+,Al)(Si,Al)4O10(OH)2
P VivianiteFe32+(PO4)2 · 8H2O
K Glauconite(K,Na)(Mg,Fe2+,Fe3+)(Fe3+,Al)(Si,Al)4O10(OH)2
Fe Goethiteα-Fe3+O(OH)
Fe Glauconite(K,Na)(Mg,Fe2+,Fe3+)(Fe3+,Al)(Si,Al)4O10(OH)2
Fe Limonite(Fe,O,OH,H2O)
Fe VivianiteFe32+(PO4)2 · 8H2O

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

5.333 - 23.03 Ma

ID: 3192743
Cenozoic sedimentary rocks

Age: Miocene (5.333 - 23.03 Ma)

Lithology: Sedimentary rocks

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]

56 - 66 Ma

ID: 2947558
Pamunkey Group; Aquia Formation

Age: Paleocene (56 - 66 Ma)

Stratigraphic Name: Aquia Formation

Description: Dark green to gray-green, argillaceous, highly glauconitic, well-sorted fine- to medium-grained sand; locally indurated shell beds; thickness 0 to 100 feet.

Comments: Original map source: In 1995 the Water Resources Division of the U.S. Geological Survey digitized the geologic map of Maryland from the 1968 paper map (Reference MD001). Information about products from the Maryland Geological Survey can be found at

Lithology: Major:{sand}

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]

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


Sort by

Year (asc) Year (desc) Author (A-Z) Author (Z-A)
Barwick, A. R. (1951) Vivianite concretions in the Aquia Formation (middle Eocene), Anne Arundel County, Maryland: American Mineralogist: 36 (7-8): 629-630.

This page contains all mineral locality references listed on 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 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 is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Public Relations by Blytheweigh.
Copyright © and the Hudson Institute of Mineralogy 1993-2019, except where stated. Most political location boundaries are © OpenStreetMap contributors. relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: October 21, 2019 08:42:12 Page generated: February 25, 2019 22:42:38
Go to top of page