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!
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West Placer Area (Preston Placer; Sweigarts Run; Swaggarts Run; West Placer; Thornbottom Run), Cecil County, Maryland, USAi
Regional Level Types
West Placer Area (Preston Placer; Sweigarts Run; Swaggarts Run; West Placer; Thornbottom Run)Area
Cecil CountyCounty
MarylandState
USACountry

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Latitude & Longitude (WGS84):
39° 43' 8'' North , 76° 10' 37'' West
Latitude & Longitude (decimal):
39.71889,-76.17722
GeoHash:
G#: dr1cfw97q
GRN:
N27W43
Type:
Area
Köppen climate type:
Cfa : Humid subtropical climate
Mindat Locality ID:
143192
Long-form identifier:
mindat:1:2:143192:9
GUID (UUID V4):
0


Alluvial chromite concentration along Swaggert Run, worked as far back as 1844. The area was prospected for chromite yield again during both World War I and World War II.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List


2 valid minerals.

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 4 - Oxides and Hydroxides
ⓘChromite4.BB.05Fe2+Cr3+2O4
ⓘMagnetite4.BB.05Fe2+Fe3+2O4

List of minerals for each chemical element

OOxygen
Oⓘ ChromiteFe2+Cr23+O4
Oⓘ MagnetiteFe2+Fe23+O4
CrChromium
Crⓘ ChromiteFe2+Cr23+O4
FeIron
Feⓘ ChromiteFe2+Cr23+O4
Feⓘ MagnetiteFe2+Fe23+O4

Other Databases

Link to USGS MRDS:10243287

Other Regions, Features and Areas containing this locality

North AmericaContinent
North America PlateTectonic Plate
USA

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.

References

Singewald, J. T. (1928) Notes on feldspar, quartz, chrome and manganese in Maryland: Maryland Geological Survey vol. 12 part 2: 91-194.
Jermian, G. D. (1943) War Minerals Report #5 & 7: U. S. Bureau of Mines.
Pearre, N. & A. V. Heyl (1960) Mineral deposits in serpentine rocks of the Piedmont Upland, Maryland, Pennsylvania and Delaware: U. S. Geological Survey: Bulletin 1082K: 784-785.
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