RockWoofSketch map
Woof’s favorite find
Bull Neck Mine
We picked it because its USGS record mentions 3 gem or collectible minerals (Quartz, Gold, Silver) and 6 of our card minerals overall. No other named site here scores as high on both counts. USGS lists it as past producer for Gold. Minerals mentioned: Quartz, Gold, Feldspar, Pyrite, Galena, Silver. Approx. location 38.965, -77.216. 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.
Was producing when the record was made.
Status terms come from USGS MRDS records.
Mineral cards
Copper
Mohs 2.5–3. Native copper is soft and turns green as it weathers. Mindat
12 sites
Pyrite
Mohs 6–6.5. Brassy “fool’s gold,” often cubic. Mindat
4 sites
Silver
Mohs 2.5–3. Native silver tarnishes black. Mindat
4 sites
Quartz
Mohs 7. Six-sided points; smoky quartz is NH’s state gem. Mindat
3 sites
Gold
Mohs 2.5–3. Soft, heavy and bright yellow; it doesn’t tarnish. Mindat
2 sites
Mica
Mohs 2–3. Peels into thin, flexible, shiny sheets. Mindat
2 sites
Garnet
Mohs 6.5–7.5. Usually deep red, round many-faced crystals. Mindat
1 site
Feldspar
Mohs 6–6.5. Blocky crystals with flat cleavage faces. Mindat
1 site
Counts are sites whose USGS record mentions the mineral or commodity. Hardness from Mindat.
Minerals recorded here
Malachite 4Shale 3Chalcopyrite 2Chalcocite 2Gold 2Bornite 1Hematite 1Gneiss 1Clay 1Sandstone 1Garnet 1Quartz 1Commodities
Copper 11Granite 6Silver 3Iron 2Gold 2Mica 1Asbestos 1Slate 1Dimension 1Sites
| Site | Commodity | Minerals recorded | Status | Approx. location |
|---|---|---|---|---|
| Chantilly Prospect A | Copper | Bornite, Chalcocite | Occurrence | 38.889, -77.419 |
| Spencer Farm Prospect | Copper | Chalcocite, Malachite | Occurrence | 38.904, -77.473 |
| Theodora Copper Mine | Copper | Chalcopyrite | Past Producer | 38.950, -77.423 |
| Jenkins Farm Prospect | Copper | Chalcopyrite, Malachite | Occurrence | 38.984, -77.327 |
| Clay Deposit Sw of Pohick | — | Clay | Occurrence | 38.693, -77.219 |
| Schist Prospect | — | Garnet, Quartz | Occurrence | 38.766, -77.405 |
| Graham-Virginia Granite Quarry | Granite | Gneiss | Producer | 38.688, -77.260 |
| Bull Run Occurrence | Gold | Gold | Occurrence | 38.838, -77.280 |
| Bull Neck Mine | Gold | Gold | Past Producer | 38.965, -77.216 |
| Greenbriar Prospect | Iron | Hematite, Malachite | Occurrence | 38.870, -77.404 |
| Chantilly Prospect B | Copper | Malachite | Occurrence | 38.884, -77.416 |
| Shale Prospect South of Bull Run | — | Sandstone, Shale | Occurrence | 38.813, -77.491 |
| Shale Prospect Ne of Chantilly | — | Shale | Occurrence | 38.903, -77.404 |
| Shale Prospect Se of Floris | — | Shale | Occurrence | 38.923, -77.398 |
| Occoquan Quarry | Granite | — | Past Producer | 38.682, -77.254 |
| Unnamed Specularite Occurrence | Iron | — | Occurrence | 38.870, -77.404 |
| Occoquan Quarry No. 1 | Granite | — | Past Producer | 38.695, -77.262 |
| No. 2 | Granite | — | Producer | 38.696, -77.262 |
| Chantilly Prospect | Copper | — | Prospect | 38.889, -77.419 |
| Fairfax Quarry Prospect | Copper | — | Prospect | 38.826, -77.488 |
| Occoquan Quarry No. 2 | Granite | — | Past Producer | 38.695, -77.261 |
| Unnamed Malachite Prospect | Copper | — | Prospect | 38.884, -77.415 |
| Schist Prospect | Mica | — | Prospect | 38.766, -77.405 |
| Hise Prospect | Asbestos | — | Occurrence | 38.936, -77.304 |
| Quantico Slate Deposits | Slate, Dimension | — | Past Producer | 38.692, -77.245 |
| Annandale Quarry | Granite | — | Past Producer | 38.836, -77.216 |
| Jenkins Farm Mine | Copper | — | Past Producer | 38.984, -77.327 |
| Spencer Farm Prospect | Copper | — | Occurrence | 38.904, -77.473 |
Fossil collections
The Paleobiology Database lists 1 fossil collection records in Fairfax County. These are research records, not public dig sites.
Nearby counties
Loudoun County · Prince William County · Fauquier County · Clarke County · Stafford 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