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.
Log InRegister
Quick Links : The Mindat ManualThe Rock H. Currier Digital LibraryMindat Newsletter [Free Download]
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 ElementsThe Rock H. Currier Digital LibraryGeologic TimeExplore Fossils
Minerals by PropertiesMinerals by ChemistryMineral Visual ExplorerAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
Mining CompaniesStatisticsUsersMineral MuseumsClubs & OrganizationsMineral Shows & EventsThe Mindat DirectoryDevice SettingsThe Mineral QuizTime Machine
Photo SearchPhoto GalleriesSearch by ColorPhoto Colour ExplorerNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryPhotography

Holbrook, Baltimore County, Maryland, USAi
Regional Level Types
HolbrookUnincorporated Area
Baltimore CountyCounty
MarylandState
USACountry

This page is currently not sponsored. Click here to sponsor this page.
PhotosMapsSearch
05612530017272071191864.jpg
View of Fenced in Shaft

Weir Mine, Holbrook, Baltimore County, Maryland, USA
02342070017272071201788.jpg
Fenced in Shafts

Weir Mine, Holbrook, Baltimore County, Maryland, USA
04475320017272035652065.jpg
Chalcedony

Weir Mine, Holbrook, Baltimore County, Maryland, USA
05612530017272071191864.jpg
View of Fenced in Shaft

Weir Mine, Holbrook, Baltimore County, Maryland, USA
02342070017272071201788.jpg
Fenced in Shafts

Weir Mine, Holbrook, Baltimore County, Maryland, USA
04475320017272035652065.jpg
Chalcedony

Weir Mine, Holbrook, Baltimore County, Maryland, USA
05612530017272071191864.jpg
View of Fenced in Shaft

Weir Mine, Holbrook, Baltimore County, Maryland, USA
02342070017272071201788.jpg
Fenced in Shafts

Weir Mine, Holbrook, Baltimore County, Maryland, USA
Latitude & Longitude (WGS84):
39° 23' 40'' North , 76° 51' 9'' West
Latitude & Longitude (decimal):
39.39455,-76.85275
GeoHash:
G#: dr1255t9c
GRN:
N27W43
Type:
Unincorporated Area
Köppen climate type:
Cfa : Humid subtropical climate
Mindat Locality ID:
251709
Long-form identifier:
mindat:1:2:251709:7
GUID (UUID V4):
0


An area in west Baltimore County consisting of the Soldier's Delight serpentine barrens. Many former chromite mines and placers are located within the barrens.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Commodity List

This is a list of exploitable or exploited mineral commodities recorded from this region.


Mineral List

Mineral list contains entries from the region specified including sub-localities

7 valid minerals.

Detailed Mineral List:

ⓘ Calcite
Formula: CaCO3
ⓘ 'Chlorite Group'
ⓘ Chromite
Formula: Fe2+Cr3+2O4
ⓘ Clinochlore ?
Formula: Mg5Al(AlSi3O10)(OH)8
ⓘ Clinochlore var. Chromium-bearing Clinochlore ?
Formula: Mg5(Al,Cr)2Si3O10(OH)8
References:
Stuart Herring CollectionIdentified by Stuart Herring: Visual Identification
ⓘ 'Deweylite'
Formula: Mg4Si3O10 · 6H2O ?
ⓘ Goethite
Formula: Fe3+O(OH)
References:
Stuart Herring
ⓘ Magnesite
Formula: MgCO3
ⓘ Quartz
Formula: SiO2
ⓘ Quartz var. Agate
Formula: SiO2
References:
Stuart Herring CollectionIdentified by Stuart Herring: Visual Identification
ⓘ Quartz var. Chalcedony
Formula: SiO2
ⓘ 'Serpentine Subgroup'
Formula: D3[Si2O5](OH)4
ⓘ Talc
Formula: Mg3Si4O10(OH)2

List of minerals arranged by Strunz 10th Edition classification

Group 4 - Oxides and Hydroxides
ⓘGoethite4.00.Fe3+O(OH)
ⓘChromite4.BB.05Fe2+Cr3+2O4
ⓘQuartz
var. Agate		4.DA.05SiO2
ⓘvar. Chalcedony4.DA.05SiO2
ⓘ4.DA.05SiO2
Group 5 - Nitrates and Carbonates
ⓘCalcite5.AB.05CaCO3
ⓘMagnesite5.AB.05MgCO3
Group 9 - Silicates
ⓘTalc9.EC.05Mg3Si4O10(OH)2
ⓘClinochlore ?9.EC.55Mg5Al(AlSi3O10)(OH)8
ⓘvar. Chromium-bearing Clinochlore ?9.EC.55Mg5(Al,Cr)2Si3O10(OH)8
Unclassified
ⓘ'Chlorite Group'-
ⓘ'Deweylite'-Mg4Si3O10 · 6H2O ?
ⓘ'Serpentine Subgroup'-D3[Si2O5](OH)4

List of minerals for each chemical element

HHydrogen
Hⓘ ClinochloreMg5Al(AlSi3O10)(OH)8
Hⓘ DeweyliteMg4Si3O10 · 6H2O ?
Hⓘ GoethiteFe3+O(OH)
Hⓘ Clinochlore var. Chromium-bearing ClinochloreMg5(Al,Cr)2Si3O10(OH)8
Hⓘ TalcMg3Si4O10(OH)2
Hⓘ Serpentine SubgroupD3[Si2O5](OH)4
CCarbon
Cⓘ CalciteCaCO3
Cⓘ MagnesiteMgCO3
OOxygen
Oⓘ Quartz var. AgateSiO2
Oⓘ CalciteCaCO3
Oⓘ Quartz var. ChalcedonySiO2
Oⓘ ChromiteFe2+Cr23+O4
Oⓘ ClinochloreMg5Al(AlSi3O10)(OH)8
Oⓘ DeweyliteMg4Si3O10 · 6H2O ?
Oⓘ GoethiteFe3+O(OH)
Oⓘ Clinochlore var. Chromium-bearing ClinochloreMg5(Al,Cr)2Si3O10(OH)8
Oⓘ MagnesiteMgCO3
Oⓘ QuartzSiO2
Oⓘ TalcMg3Si4O10(OH)2
Oⓘ Serpentine SubgroupD3[Si2O5](OH)4
MgMagnesium
Mgⓘ ClinochloreMg5Al(AlSi3O10)(OH)8
Mgⓘ DeweyliteMg4Si3O10 · 6H2O ?
Mgⓘ Clinochlore var. Chromium-bearing ClinochloreMg5(Al,Cr)2Si3O10(OH)8
Mgⓘ MagnesiteMgCO3
Mgⓘ TalcMg3Si4O10(OH)2
AlAluminium
Alⓘ ClinochloreMg5Al(AlSi3O10)(OH)8
Alⓘ Clinochlore var. Chromium-bearing ClinochloreMg5(Al,Cr)2Si3O10(OH)8
SiSilicon
Siⓘ Quartz var. AgateSiO2
Siⓘ Quartz var. ChalcedonySiO2
Siⓘ ClinochloreMg5Al(AlSi3O10)(OH)8
Siⓘ DeweyliteMg4Si3O10 · 6H2O ?
Siⓘ Clinochlore var. Chromium-bearing ClinochloreMg5(Al,Cr)2Si3O10(OH)8
Siⓘ QuartzSiO2
Siⓘ TalcMg3Si4O10(OH)2
Siⓘ Serpentine SubgroupD3[Si2O5](OH)4
CaCalcium
Caⓘ CalciteCaCO3
CrChromium
Crⓘ ChromiteFe2+Cr23+O4
Crⓘ Clinochlore var. Chromium-bearing ClinochloreMg5(Al,Cr)2Si3O10(OH)8
FeIron
Feⓘ ChromiteFe2+Cr23+O4
Feⓘ GoethiteFe3+O(OH)

Other Databases

GeoNames ID:4358221

Localities in this Region

USA

Other Regions, Features and Areas containing this locality

North AmericaContinent
North America PlateTectonic Plate

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.
Quick NavTopCommoditiesMineral ListOther DatabasesLocalities in RegionOther Regions
 
and/or  
Mindat.org® is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Mindat® and mindat.org® are registered trademarks of the Hudson Institute of Mineralogy.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2026, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 by Jolyon Ralph and Ida Chau.
Content on this site may not be used to train, fine-tune, or otherwise develop artificial intelligence or machine learning models without prior written permission - see our Terms & Conditions.
To cite: Ralph, J., Von Bargen, D., Martynov, P., Zhang, J., Que, X., Prabhu, A., Morrison, S. M., Li, W., Chen, W., & Ma, X. (2025). Mindat.org: The open access mineralogy database to accelerate data-intensive geoscience research. American Mineralogist, 110(6), 833–844. doi:10.2138/am-2024-9486.
Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: September 6, 2026 08:42:46 Page updated: July 31, 2025 01:15:59
Go to top of page