Vote for your favorite mineral in #MinCup26! - Quartz vs. Asagiite
It's a classic vs a newbie as the most common named mineral in the crust Quartz is up against an exceedingly-rare sea foam-green mineral discovered just a few years ago Asagiite.
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McComas Ore Banks, Baltimore County, Maryland, USAi
Regional Level Types
McComas Ore Banks- not defined -
Baltimore CountyCounty
MarylandState
USACountry

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Latitude & Longitude (WGS84):
39° 36' 51'' North , 76° 36' 55'' West
Latitude & Longitude (decimal):
39.61417,-76.61528
GRN:
N27W43
Köppen climate type:
Cfa : Humid subtropical climate
Nearest Settlements:
PlacePopulationDistance
Jarrettsville2,916 (2011)11.8km
Hunt Valley23,915 (2012)12.9km
Cockeysville20,776 (2011)15.0km
New Freedom4,585 (2017)15.6km
Stewartstown2,305 (2017)15.6km
Nearest Clubs:
Local clubs are the best way to get access to collecting localities
ClubLocationDistance
Baltimore Mineral SocietyBaltimore, Maryland36km
Chesapeake Gem & Mineral SocietyBaltimore, Maryland36km
Gem Cutters Guild of Baltimore, Inc.Baltimore, Maryland36km
Mason-Dixon Rock, Mineral, Gemological, & Lapidary ClubHanover, Pennsylvania38km
Central Maryland Rock and Mineral Collectors ExchangeElkridge, Maryland45km
Mindat Locality ID:
142969
Long-form identifier:
mindat:1:2:142969:8
GUID (UUID V4):
0


This was a small deposit of titaniferous iron ore - reportedly magnetite and chromite - in serpentinite.

Commodities (Major) - Iron
Development Status: Past Producer

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Commodity List

This is a list of exploitable or exploited mineral commodities recorded at this locality.


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
Unclassified
ⓘ'Serpentine Subgroup'-D3[Si2O5](OH)4

List of minerals for each chemical element

HHydrogen
Hⓘ Serpentine SubgroupD3[Si2O5](OH)4
OOxygen
Oⓘ ChromiteFe2+Cr23+O4
Oⓘ MagnetiteFe2+Fe23+O4
Oⓘ Serpentine SubgroupD3[Si2O5](OH)4
SiSilicon
Siⓘ Serpentine SubgroupD3[Si2O5](OH)4
CrChromium
Crⓘ ChromiteFe2+Cr23+O4
FeIron
Feⓘ ChromiteFe2+Cr23+O4
Feⓘ MagnetiteFe2+Fe23+O4

Other Databases

Link to USGS MRDS:10121287

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. (1911) Report on the iron ores of Maryland: Maryland Geological Survey Vol. 9 Part 3: 222 & 321.
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: 707-833.
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