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

Hurdtown Apatite Mine, Hurdtown, Jefferson Township, Morris Co., New Jersey, USAi
Regional Level Types
Hurdtown Apatite MineMine
Hurdtown- not defined -
Jefferson TownshipTownship
Morris Co.County
New JerseyState

This page is currently not sponsored. Click here to sponsor this page.
Lock Map
Latitude & Longitude (WGS84): 40° 58' 0'' North , 74° 34' 59'' West
Latitude & Longitude (decimal): 40.96667,-74.58333
GeoHash:G#: dr6cncf04
Locality type:Mine
Köppen climate type:Cfa : Humid subtropical climate

An iron-phosphate mine located near Hurdtown, about 5 miles North of Dover. Started and closed before 1855. Ore was a pyritiferous magnetite.

Although apatite is very common in the iron ores of northern New Jersey, this is one of the very few ore deposits where it becomes a major component. Unfortunately, this prospect is so old, pre-1855, and so sketchily described that a precise understanding of the nature of the ore may be impossible. Bayley(1910) says that apatite "occurs in irregular seams, often intermixed with pyrrhotite...". This suggests secondary hydrothermal reworking, possibly during the long period of pegmatite intrusion and hydrothermal activity that followed the Ottawan orogeny. Unfortunately, this is anything but clear. Elsewhere, Bayley notes that the apatite is "usually in aggregates mixed with all the other minerals mentioned". This sounds more like the dispersed occurrence common throughout the region.

It seems that the ore was to low grade and sulphidic to be mined for iron and to low grade to be mined for phosphate.

Regions containing this locality

North America Plate

Plate - 4,950 mineral species & varietal names listed

Select Mineral List Type

Standard Detailed Strunz Dana Chemical Elements

Mineral List

6 valid minerals.

Detailed Mineral List:

Description: Famous for large apatite crystals now extremely rare to find.
Reference: The Iron Mines of NJ (1910), Bayley:332; NJ State Geol. Ann. Rpt. (1856):167; State NJ Bull. #50:192.
Formula: CaCO3
Reference: The Iron Mines of NJ (1910), Bayley:332; NJ State Geol. Ann. Rpt. (1856):166; State NJ Bull. #50:192.
'Feldspar Group'
Reference: NJ State Geol. Ann. Rpt. (1856):167.
Formula: ☐{Ca2}{Fe2+4Al}(AlSi7O22)(OH)2
Reference: NJ State Geol. Ann. Rpt. (1856):167.
Formula: (Fe,O,OH,H2O)
Reference: NJ State Geol. Ann. Rpt. (1856):167.
Formula: Fe2+Fe3+2O4
Reference: The Iron Mines of NJ (1910), Bayley:332; NJ State Geol. Ann. Rpt. (1856):166; State NJ Bull. #50:192.
'Mica Group'
Reference: NJ State Geol. Ann. Rpt. (1856):167.
Formula: FeS2
Reference: The Iron Mines of NJ (1910), Bayley:332; NJ State Geol. Ann. Rpt. (1856):167; State NJ Bull. #50:192.
Formula: Fe7S8
Reference: The Iron Mines of NJ (1910), Bayley:332; NJ State Geol. Ann. Rpt. (1856):166; State NJ Bull. #50:192.
Formula: SiO2
Reference: NJ State Geol. Ann. Rpt. (1856):167.

List of minerals arranged by Strunz 10th Edition classification

Group 2 - Sulphides and Sulfosalts
Group 4 - Oxides and Hydroxides
Group 5 - Nitrates and Carbonates
Group 9 - Silicates
Unclassified Minerals, Rocks, etc.
'Feldspar Group'-
'Mica Group'-

List of minerals arranged by Dana 8th Edition classification

Group 2 - SULFIDES
AmXp, with m:p = 1:1
AmBnXp, with (m+n):p = 1:2
Group 75 - TECTOSILICATES Si Tetrahedral Frameworks
Si Tetrahedral Frameworks - SiO2 with [4] coordinated Si
Unclassified Minerals, Rocks, etc.
'Feldspar Group'-
'Mica Group'-

List of minerals for each chemical element

H Ferro-hornblende☐{Ca2}{Fe42+Al}(AlSi7O22)(OH)2
H Limonite(Fe,O,OH,H2O)
C CalciteCaCO3
O CalciteCaCO3
O Ferro-hornblende☐{Ca2}{Fe42+Al}(AlSi7O22)(OH)2
O Limonite(Fe,O,OH,H2O)
O MagnetiteFe2+Fe23+O4
O QuartzSiO2
Al Ferro-hornblende☐{Ca2}{Fe42+Al}(AlSi7O22)(OH)2
Si Ferro-hornblende☐{Ca2}{Fe42+Al}(AlSi7O22)(OH)2
Si QuartzSiO2
S PyriteFeS2
S PyrrhotiteFe7S8
Ca CalciteCaCO3
Ca Ferro-hornblende☐{Ca2}{Fe42+Al}(AlSi7O22)(OH)2
Fe Ferro-hornblende☐{Ca2}{Fe42+Al}(AlSi7O22)(OH)2
Fe Limonite(Fe,O,OH,H2O)
Fe MagnetiteFe2+Fe23+O4
Fe PyriteFeS2
Fe PyrrhotiteFe7S8

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

1000 - 1200 Ma

ID: 2915938
Hornblende Granite

Age: Stenian (1000 - 1200 Ma)

Stratigraphic Name: Byram Intrusive Suite

Description: Pinkish-gray- to medium-buff-weathering, pinkish-white or light-pinkish-gray, medium- to coarse-grained, gneissoid to indistinctly foliated granite and sparse granite gneiss composed principally of microcline microperthite, quartz, oligoclase, and hornblende. Some phases are quartz syenite or quartz monzonite. Includes small bodies of pegmatite and amphibolite not shown on map. U-Pb age approximately 1,090 Ma (Drake and others, 1991b).

Comments: Byram Intrusive Suite (Middle Proterozoic) (Drake, 1984) Original map source: Dalton, R.F., Herman, G.C., Monteverde, D.H., Pristas, R.S., Sugarman, P.J., and Volkert, R.A., 1999, New Jersey Department of Environmental Protection, Bedrock Geology and Topographic Base Maps of New Jersey: New Jersey Geological Survey CD Series CD 00

Lithology: Major:{granite}, Minor:{gneiss,quartz syenite,quartz monzonite}, Incidental:{pegmatite, amphibolite}

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]

1000 - 1600 Ma

ID: 3188605
Mesoproterozoic crystalline metamorphic rocks

Age: Mesoproterozoic (1000 - 1600 Ma)

Lithology: Paragneiss; paragneiss

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)
New Jersey State Geologist Annual Reports: (1855): 166-168; (1868): 603-606; (1879): 71.
Bayley (1910) The Iron Mines of New Jersey: 332-333.

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. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: May 23, 2019 12:28:09 Page generated: December 18, 2018 19:09:16
Go to top of page