Found alongside
Gold
Mohs 2.5–3. Soft, heavy and bright yellow; it doesn’t tarnish. Mindat
33 sites
Silver
Mohs 2.5–3. Native silver tarnishes black. Mindat
7 sites
Copper
Mohs 2.5–3. Native copper is soft and turns green as it weathers. Mindat
6 sites
Quartz
Mohs 7. Six-sided points; smoky quartz is NH’s state gem. Mindat
5 sites
Pyrite
Mohs 6–6.5. Brassy “fool’s gold,” often cubic. Mindat
3 sites
Galena
Mohs 2.5–2.75. Heavy, silvery lead ore that breaks into cubes. Mindat
1 site
Counts are sites whose USGS record mentions the mineral or commodity. Hardness from Mindat.
By county
Montgomery County (26) · Frederick County (6) · Baltimore city (1)
Sites
| Site | Commodity | Minerals recorded | Status | Approx. location |
|---|---|---|---|---|
| Maryland Mine | Gold | Chalcopyrite, Galena, Pyrite, Pyrrhotite | Past Producer | 38.996, -77.232 |
| Harrison Mine | Gold | Gold | Past Producer | 38.999, -77.198 |
| Rock Run Gold Placers | Gold | Gold | Occurrence | 38.989, -77.208 |
| Bethesda Mine | Gold | Gold, Quartz | Past Producer | 38.997, -77.127 |
| Sawyer Mine | Gold | Quartz | Past Producer | 38.988, -77.204 |
| Irma Mine | Gold | Quartz | Past Producer | 38.986, -77.201 |
| Lynch Mine | Gold | Quartz | Past Producer | 38.987, -77.191 |
| New London Mine Linganore | Copper | — | Past Producer | 39.421, -77.258 |
| Sawyer Mine & 5 Additional Mines | Gold | — | Past Producer | 38.988, -77.204 |
| Bethesda Mine | Gold | — | Past Producer | 38.997, -77.127 |
| Huddleston Mine | Gold | — | Past Producer | 39.052, -77.142 |
| Bogley Mine | Gold | — | Past Producer | 39.060, -77.173 |
| Montgomery Mine | Gold | — | Past Producer | 39.014, -77.214 |
| Frederick Gold Mine | Gold, Silver | — | Past Producer | 39.417, -77.491 |
| Lynch Mine | Gold | — | Past Producer | 38.987, -77.191 |
| Eagle Mine | Gold | — | Past Producer | 39.003, -77.200 |
| Miller Mine | Gold | — | Past Producer | 38.989, -77.117 |
| Bogley Mine | Gold | — | Past Producer | 39.063, -77.174 |
| Harrison Mine | Gold | — | Past Producer | 38.999, -77.198 |
| Ellicott Mine | Gold | — | Past Producer | 39.000, -77.000 |
| Sawyer Mine | Gold | — | Past Producer | 38.988, -77.204 |
| Rock Run Gold Placers | Gold | — | Past Producer | 38.989, -77.208 |
| Watson Mine | Gold | — | Past Producer | 39.003, -77.234 |
| Maryland Mine | Gold | — | Past Producer | 38.996, -77.232 |
| New London Mine | — | — | Past Producer | 39.419, -77.260 |
| Mountain View Mine | — | — | Prospect | 39.547, -77.202 |
| Huddleston Mine | Gold | — | Past Producer | 39.055, -77.146 |
| Eiler Prospect | — | — | Prospect | 39.541, -77.203 |
| Montgomery Mine | Gold | — | Past Producer | 39.014, -77.213 |
| Ford Mine | Gold | — | Past Producer | 39.011, -77.237 |
| American Smelt & Refin/Baltimore Md | Gold | — | Plant | 39.290, -76.609 |
| Bethesda Mine | Gold | — | Past Producer | 38.997, -77.127 |
| Liberty Mine | — | — | Past Producer | 39.513, -77.254 |
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