RockWoof
Check access before you go. Most sites listed here are old mines, quarries or prospects, and many are on private land or active mining claims. Get the landowner's permission, check the rules of the agency that manages any public land, and never enter mine workings. Locations are approximate.

Sketch map

Forsythe Mine/Rice Magnetite Mine (Past Producer)Forsythe Mine (Past Producer)Rice Ore Bank (Past Producer)Brighton Dam Road Quarry (Past Producer)Hanna Quarry + 1 more nearby (Past Producer)Melvin Quarry + 2 more nearby (Past Producer)Ben Murphy Mica-Beryl Mine (Past Producer)Warfield Quarry + 2 more nearby (Past Producer)Patapsco Quarry + 5 more nearby (Past Producer)Biddison Pegmatite Deposit + 1 more nearby (Prospect)Maryland Mica Company Mine + 1 more nearby (Past Producer)George Iager Beryl-Mica Prospects (Past Producer)East Marriottsville Quarry (Past Producer)Baltimore Feldspar Company Quarries (Past Producer)Brown Quarries (Past Producer)Gudelsky Farm (Prospect)Arlington No. 1 Quarry + 3 more nearby (Past Producer)Moody Quarry (Past Producer)Dorseys Run Quarry No. 1 + 1 more nearby (Past Producer)Gary Quarry (Past Producer)Theis Quarry No. 1 + 3 more nearby (Past Producer)Streker Quarry + 3 more nearby (Past Producer)Haslup Ore Bank (Past Producer)Fisher and Carozza Quarries (Past Producer)Weber Quarry + 1 more nearby (Past Producer)Mount St.Clement College Quarry (Past Producer)Pindell Quarries No. 1 + 1 more nearby (Past Producer)Pindell Quarries No. 2 (Past Producer)O'Connor Farm Quarries + 1 more nearby (Past Producer)Talbott Ore Bank (Past Producer)Hobbs Ore Bank (Past Producer)Brooks Ore Bank (Past Producer)
Past ProducerProducerProspectOccurrenceStatus unknown
32 paw pins; nearby sites are grouped into one pin. Hover or tap a pin for the site name. 2 site(s) with USGS coordinates outside the outline are not pinned. County outline: US Census Bureau cartographic boundary file (2023). Locations approximate.

Woof’s favorite find

Marriottsville Quarry

We picked it because its USGS record mentions 1 gem or collectible mineral (Quartz) and 1 of our card minerals overall. That ties with 1 other site(s), so we broke the tie by mine status (past producers first), then USGS record quality, then name. USGS lists it as past producer for Quartz. Minerals mentioned: Quartz. Approx. location 39.365, -76.899. USGS record.

Ask first: a USGS record doesn’t mean you can visit. Find out who owns the land and get permission before collecting.

Field cards: what kind of sites?

56
Past Producer

Produced ore or material at some point in the past.

3
Prospect

Explored or test-dug, with no recorded production.

Status terms come from USGS MRDS records.

Mineral cards

Counts are sites whose USGS record mentions the mineral or commodity. Hardness from Mindat.

Minerals recorded here

Marble 1Limonite 1

Commodities

Feldspar 42Iron 8Mica 3Quartz 2Marble 1Dimension 1

Sites (first 40)

SiteCommodityMinerals recordedStatusApprox. location
Forsythe Mine/Rice Magnetite MineIronLimonitePast Producer39.350, -77.044
Brighton Dam Road QuarryMarble, DimensionMarblePast Producer39.196, -76.986
Marriottsville QuarryQuartz—Past Producer39.365, -76.899
Patapsco QuarryQuartz—Past Producer39.344, -76.902
Arlington No. 1 QuarryFeldspar—Past Producer39.315, -76.854
Hobbs Ore BankIron—Past Producer39.184, -76.730
Rice Ore BankIron—Past Producer39.335, -77.017
Fisher and Carozza QuarriesFeldspar—Past Producer39.256, -76.782
Warfield QuarryFeldspar—Past Producer39.351, -76.900
Pindell Quarries No. 1Feldspar—Past Producer39.244, -76.761
Dorseys Run Quarry No. 1Feldspar—Past Producer39.313, -76.829
Ben Murphy Mica-Beryl Mine——Past Producer39.139, -76.917
Zepp QuarryFeldspar—Past Producer39.346, -76.903
Moody QuarryFeldspar—Past Producer39.307, -76.855
Pindell Quarries No. 2Feldspar—Past Producer39.243, -76.758
Biddison Pegmatite Deposit——Prospect39.331, -76.907
Melvin QuarryFeldspar—Past Producer39.232, -76.919
Harold Stromberg QuarryFeldspar—Past Producer39.340, -76.909
Dorseys Quarry No. 2Feldspar—Past Producer39.314, -76.830
Streker QuarryFeldspar—Past Producer39.301, -76.807
East Marriottsville QuarryFeldspar—Past Producer39.351, -76.898
Arlington No. 2 QuarryFeldspar—Past Producer39.314, -76.848
Brown Ore BanksIron—Past Producer39.183, -76.723
Weber QuarryFeldspar—Past Producer39.252, -76.781
Theis Quarry No. 1Feldspar—Past Producer39.313, -76.798
Wharton QuarryFeldspar—Past Producer39.253, -76.777
Frost QuarryFeldspar—Past Producer39.312, -76.857
Hanna QuarryFeldspar—Past Producer39.344, -76.918
Melvin Quarry No. 1Feldspar—Past Producer39.230, -76.919
Brooks Ore BankIron—Past Producer39.201, -76.717
Mathews QuarryFeldspar—Past Producer39.336, -76.905
Fagan QuarriesFeldspar—Past Producer39.306, -76.803
South Marriottsville QuarryFeldspar—Past Producer39.349, -76.901
Maryland Mica Company MineMica—Past Producer39.172, -76.904
Melvin Quarry No. 2Feldspar—Past Producer39.228, -76.918
Theis Quarry No. 2Feldspar—Past Producer39.312, -76.797
Mount St.Clement College QuarryFeldspar—Past Producer39.254, -76.772
Haslup Ore BankIron—Past Producer39.144, -76.793
O'Connor Farm QuarriesFeldspar—Past Producer39.239, -76.752
Baltimore Feldspar Company QuarryFeldspar—Past Producer39.247, -76.766

Fossil collections

The Paleobiology Database lists 3 fossil collection records in Howard County. These are research records, not public dig sites.

Nearby counties

Baltimore County · Anne Arundel County · Carroll County · Baltimore city · Prince George's County

Maryland mineral guides

Back to all Maryland counties.

Related articles

How we built this page: we counted named sites in the USGS Mineral Resources Data System (MRDS) for this area, left out sand, gravel, crushed stone, clay pits and unnamed sites, grouped them by Census county, and linked every site to its USGS record. We did not visit these sites, and MRDS does not tell you who owns the land or whether collecting is allowed.

Source: USGS Mineral Resources Data System (MRDS). USGS ceased systematic updates to MRDS around 2011, so status and details may be out of date. Each site links to its USGS record.

Updated