RockWoofSketch map
Woof’s favorite find
Fort Knox Prospect
We picked it because its USGS record mentions 2 gem or collectible minerals (Gold, Silver) and 3 of our card minerals overall. No other named site here scores as high on both counts. USGS lists it as unknown. Minerals mentioned: Gold, Copper, Silver. Approx. location 44.571, -68.814. 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?
Produced ore or material at some point in the past.
Explored or test-dug, with no recorded production.
The mineral was noted here, without development.
Status not recorded.
Status terms come from USGS MRDS records.
Mineral cards
Gold
Mohs 2.5–3. Soft, heavy and bright yellow; it doesn’t tarnish. Mindat
5 sites
Silver
Mohs 2.5–3. Native silver tarnishes black. Mindat
3 sites
Copper
Mohs 2.5–3. Native copper is soft and turns green as it weathers. Mindat
2 sites
Pyrite
Mohs 6–6.5. Brassy “fool’s gold,” often cubic. Mindat
1 site
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.
Minerals recorded here
Arsenopyrite 1Galena 1Molybdenite 1Commodities
Granite 13Gold 3Slate 2Dimension 2Molybdenum 1Silver 1Sites
| Site | Commodity | Minerals recorded | Status | Approx. location |
|---|---|---|---|---|
| Mt. Waldo; Mosquito Mtn. | Molybdenum | Arsenopyrite, Galena, Molybdenite | Occurrence | 44.583, -68.866 |
| Mansfield Quarry | Granite | — | Past Producer | 44.621, -69.881 |
| Jackson Mine | — | — | Unknown | 44.619, -69.126 |
| Oak Hill Quarries | Granite | — | Past Producer | 44.252, -69.037 |
| Stone Prospect | Silver | — | Prospect | 44.525, -69.207 |
| Mount Waldo Quarry | Granite | — | Past Producer | 44.590, -68.884 |
| Freeman Mine | Gold | — | Prospect | 44.270, -69.021 |
| Unnamed Mine | Gold | — | Occurrence | 44.563, -69.930 |
| Fort Knox Prospect | — | — | Unknown | 44.571, -68.814 |
| Adams Oak Quarry | Granite | — | Past Producer | 44.506, -69.032 |
| Lincolnville Quarry | Granite | — | Past Producer | 44.326, -69.058 |
| Lincolnville Prospect | Gold | — | Prospect | 44.305, -69.079 |
| Heal Black Granite Quarry | Granite | — | Past Producer | 44.274, -69.102 |
| Bussey Quarry | Granite | — | Past Producer | 44.618, -69.880 |
| Bog Hill Quarry | Granite | — | Past Producer | 44.523, -68.957 |
| Hall Quarry | Granite | — | Past Producer | 44.512, -69.035 |
| Mosquito Mountain Quarry | Granite | — | Past Producer | 44.577, -68.870 |
| Heagan Quarry | Granite | — | Past Producer | 44.587, -69.851 |
| Mack Quarry | Granite | — | Past Producer | 44.568, -68.882 |
| Slate Quarry | Slate, Dimension | — | Past Producer | 44.597, -69.226 |
| Fernald Quarry | Slate, Dimension | — | Past Producer | 44.271, -69.104 |
| Kelly's Quarry | Granite | — | Past Producer | 44.582, -69.885 |
Nearby counties
Penobscot County · Hancock County · Knox County · Lincoln County · Kennebec County
Maine mineral guides
Back to all Maine counties.
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