RockWoofFound alongside
Copper
Mohs 2.5–3. Native copper is soft and turns green as it weathers. Mindat
41 sites
Silver
Mohs 2.5–3. Native silver tarnishes black. Mindat
11 sites
Pyrite
Mohs 6–6.5. Brassy “fool’s gold,” often cubic. Mindat
10 sites
Magnetite
Mohs 5.5–6.5. Black and strongly magnetic. Mindat
8 sites
Gold
Mohs 2.5–3. Soft, heavy and bright yellow; it doesn’t tarnish. Mindat
6 sites
Quartz
Mohs 7. Six-sided points; smoky quartz is NH’s state gem. Mindat
5 sites
Counts are sites whose USGS record mentions the mineral or commodity. Hardness from Mindat.
By county
Carroll County (16) · Frederick County (16) · Washington County (4) · Baltimore County (3) · Baltimore city (2)
Sites
| Site | Commodity | Minerals recorded | Status | Approx. location |
|---|---|---|---|---|
| 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 |
| Springfield | Copper | Carrollite | Past Producer | 39.383, -76.977 |
| Patapsco | Copper | Carrollite, Chalcocite, Chalcopyrite, Covellite, Magnetite, Sphalerite | Past Producer | 39.486, -76.879 |
| Liberty Mine | Copper | — | Past Producer | 39.513, -77.254 |
| Cox Mt. View Mine/Repp Mine | Copper | — | Past Producer | 39.546, -77.204 |
| Dolly Hyde Mine | Copper | — | Past Producer | 39.479, -77.227 |
| New London Mine Linganore | Copper | — | Past Producer | 39.421, -77.258 |
| Mineral Hill | Copper | — | Past Producer | 39.438, -76.932 |
| Patapsco | Copper | — | Past Producer | 39.486, -76.879 |
| Unionville | Zinc | — | Past Producer | 39.494, -77.198 |
| Roop Mine | Copper | — | Past Producer | 39.520, -77.119 |
| Bare Hills Cu Mine | Copper | — | Past Producer | 39.375, -76.664 |
| Springfield/Carrollnew Burra | Copper | — | Past Producer | 39.383, -76.977 |
| Cox Mines | — | — | Prospect | 39.551, -77.205 |
| Monroe Prospect | — | — | Prospect | 39.426, -76.948 |
| Patapsco Mines | — | — | Past Producer | 39.489, -76.877 |
| Roop Mine | — | — | Prospect | 39.520, -77.119 |
| Carroll Mine | — | — | Past Producer | 39.388, -76.971 |
| South Mountain Prospect | Copper | — | Prospect | 39.665, -77.524 |
| Bare Hills Copper Mine | Copper | — | Past Producer | 39.375, -76.664 |
| New London Mine | — | — | Past Producer | 39.419, -77.260 |
| Robert D. Repp Prospect | Copper | — | Prospect | 39.588, -77.219 |
| Mountain View Mine | — | — | Prospect | 39.547, -77.202 |
| Hines Prospects | — | — | Prospect | 39.480, -77.250 |
| Beasman Prospect | — | — | Prospect | 39.433, -76.933 |
| Israel Creek Prospects | — | — | Prospect | 39.225, -77.262 |
| Hammond Prospect | — | — | Past Producer | 39.473, -77.249 |
| Unionville Mine | — | — | Past Producer | 39.479, -77.198 |
| Mineral Hill Mine | — | — | Past Producer | 39.438, -76.930 |
| South Mountain Prospect | Copper | — | Prospect | 39.697, -77.481 |
| South Mountain Prospect | Copper | — | Prospect | 39.639, -77.537 |
| South Mountain Prospect | Copper | — | Prospect | 39.679, -77.516 |
| Eiler Prospect | — | — | Prospect | 39.541, -77.203 |
| Repp Mine | Copper | — | Past Producer | 39.522, -77.221 |
| (Facility) Cox Creek Refinery | Copper | — | Plant | 39.288, -76.616 |
| Springfield Mine | — | — | Past Producer | 39.381, -76.975 |
| American Smelt & Refin/Baltimore Md | Gold | — | Plant | 39.290, -76.609 |
| South Mountain Prospect | Copper | — | Prospect | 39.627, -77.551 |
| Liberty Mine | — | — | Past Producer | 39.513, -77.254 |
| Dolly Hyde Mine | — | — | Prospect | 39.479, -77.227 |
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