Found alongside
Magnetite
Mohs 5.5–6.5. Black and strongly magnetic. Mindat
15 sites
Pyrite
Mohs 6–6.5. Brassy “fool’s gold,” often cubic. Mindat
8 sites
Copper
Mohs 2.5–3. Native copper is soft and turns green as it weathers. Mindat
8 sites
Quartz
Mohs 7. Six-sided points; smoky quartz is NH’s state gem. Mindat
4 sites
Counts are sites whose USGS record mentions the mineral or commodity. Hardness from Mindat.
By county
Carroll County (7) · Baltimore County (4) · Harford County (4)
Sites
| Site | Commodity | Minerals recorded | Status | Approx. location |
|---|---|---|---|---|
| Dinning Mine | Titanium, Metal, Iron | Apatite, Ilmenite, Magnetite, Rutile | Producer | 39.700, -76.383 |
| Bare Hills Copper Mine | Copper | Bornite, Carrollite, Chalcopyrite, Magnetite | Past Producer | 39.375, -76.664 |
| Mineral Hill | Copper | Bornite, Carrollite, Chalcopyrite, Magnetite, Sphalerite | Past Producer | 39.438, -76.932 |
| Patapsco | Copper | Carrollite, Chalcocite, Chalcopyrite, Covellite, Magnetite, Sphalerite | Past Producer | 39.486, -76.879 |
| Glyndon | Iron, Chromium, Platinum | Chromite, Magnetite | Occurrence | 39.476, -76.817 |
| Mccomasore Bank/Norris Ore Bank | Iron | Magnetite | Past Producer | 39.614, -76.616 |
| Broad Creek Mine | Iron | Magnetite | Past Producer | 39.675, -76.262 |
| Deer Creek Mine/Cherry Hill Mine | Iron | Magnetite | Past Producer | 39.644, -76.369 |
| Shawsville Area | Iron | Magnetite | Past Producer | 39.639, -76.550 |
| Monroe Prospect | — | — | Prospect | 39.426, -76.948 |
| Patapsco Mines | — | — | Past Producer | 39.489, -76.877 |
| Triplett Placer | Chromium | — | Past Producer | 39.420, -76.848 |
| Beasman Prospect | — | — | Prospect | 39.433, -76.933 |
| Mineral Hill Mine | — | — | Past Producer | 39.438, -76.930 |
| Springfield Mine | — | — | Past Producer | 39.381, -76.975 |
Back to Rockhounding in Maryland.
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 USGS ceased systematic updates to MRDS around 2011, so status and details may be out of date.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