RockWoofSketch map
Woof’s favorite find
Cabin Branch Mine
We picked it because its USGS record mentions 5 gem or collectible minerals (Tourmaline, Quartz, Garnet, Gold, Silver) and 9 of our card minerals overall. No other named site here scores as high on both counts. USGS lists it as past producer for Sulfur-Pyrite. Minerals mentioned: Tourmaline, Quartz, Garnet, Gold, Mica, Pyrite, Galena, Copper, Silver. Approx. location 38.575, -77.348. 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?
The mineral was noted here, without development.
Produced ore or material at some point in the past.
Explored or test-dug, with no recorded production.
Status terms come from USGS MRDS records.
Mineral cards
Gold
Mohs 2.5–3. Soft, heavy and bright yellow; it doesn’t tarnish. Mindat
8 sites
Quartz
Mohs 7. Six-sided points; smoky quartz is NH’s state gem. Mindat
6 sites
Pyrite
Mohs 6–6.5. Brassy “fool’s gold,” often cubic. Mindat
5 sites
Copper
Mohs 2.5–3. Native copper is soft and turns green as it weathers. Mindat
4 sites
Tourmaline
Mohs 7–7.5. Long striated crystals, often black (schorl) or green and pink (elbaite). Mindat
1 site
Garnet
Mohs 6.5–7.5. Usually deep red, round many-faced crystals. Mindat
1 site
Mica
Mohs 2–3. Peels into thin, flexible, shiny sheets. 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
Pyrite 4Shale 3Barite 2Gold 2Clay 2Sandstone 2Malachite 1Chalcopyrite 1Galena 1Pyrrhotite 1Sphalerite 1Quartz 1Commodities
Gold 7Barium-Barite 3Copper 3Sulfur-Pyrite 3Sulfur 3Granite 1Zinc 1Lead 1Quartz 1Rock Asphalt 1Sites
| Site | Commodity | Minerals recorded | Status | Approx. location |
|---|---|---|---|---|
| Manassas Occurrence | Barium-Barite | Barite | Occurrence | 38.730, -77.473 |
| Cedar Run Mine | Barium-Barite | Barite, Pyrite | Past Producer | 38.625, -77.579 |
| Cabin Branch Mine | Sulfur-Pyrite | Chalcopyrite, Galena, Pyrite, Pyrrhotite, Sphalerite | Past Producer | 38.575, -77.348 |
| Clay Prospect S. of Wellington | — | Clay | Occurrence | 38.751, -77.567 |
| Clay Prospect Se of Dumfries | — | Clay, Quartz | Occurrence | 38.540, -77.281 |
| Greenwood Prospect | Gold | Gold | Occurrence | 38.630, -77.432 |
| Crawford Placers Prospect | Gold | Gold | Past Producer | 38.624, -77.301 |
| Brentsville Prospect | Copper | Malachite | Occurrence | 38.688, -77.499 |
| Agnewville Prospect | Sulfur-Pyrite | Pyrite | Occurrence | 38.644, -77.289 |
| Joplin Prospect | Sulfur-Pyrite | Pyrite | Occurrence | 38.567, -77.387 |
| Shale Prospect In Manassas Nat'L Park | — | Sandstone, Shale | Occurrence | 38.823, -77.511 |
| Shale Prospect Nw of Aden | — | Sandstone, Shale | Occurrence | 38.678, -77.572 |
| Shale Prospect S. of Kings Crossroads | — | Shale | Occurrence | 38.644, -77.590 |
| Manassas Quarry | Granite | — | Past Producer | 38.781, -77.515 |
| Greenwood Mine | Gold | — | Past Producer | 38.631, -77.430 |
| Joplin Prospect | Sulfur | — | Prospect | 38.570, -77.392 |
| Crawford Placers | Gold | — | Past Producer | 38.624, -77.315 |
| Agnewville Prospect | Gold, Sulfur | — | Prospect | 38.644, -77.289 |
| Brentsville Prospect | Copper | — | Occurrence | 38.689, -77.498 |
| Cabin Branch Mine | Zinc, Copper, Gold, Lead, Sulfur | — | Past Producer | 38.574, -77.347 |
| South Manassas Prospect | Barium-Barite | — | Occurrence | 38.730, -77.473 |
| W. E. Grahm & Sons Division Quarry | Quartz | — | Past Producer | 38.790, -77.624 |
| Millbrook Quarries | Rock Asphalt | — | Past Producer | 38.820, -77.711 |
Fossil collections
The Paleobiology Database lists 7 fossil collection records in Prince William County. These are research records, not public dig sites.
Nearby counties
Fauquier County · Fairfax County · Stafford County · Culpeper County · Loudoun County
Virginia mineral guides
- Beryl in Virginia
- Tourmaline in Virginia
- Quartz in Virginia
- Garnet in Virginia
- Gold in Virginia
- Mica in Virginia
Back to all Virginia 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