RockWoofBest regions by county
Ranked by the number of USGS-recorded sites, not by access or quality.
- Morris County: 331 sites; most recorded: Magnetite, Hematite, Granite
- Warren County: 155 sites; most recorded: Magnetite, Limonite, Slate
- Sussex County: 85 sites; most recorded: Magnetite, Hematite, Limonite
- Hunterdon County: 67 sites; most recorded: Magnetite, Limonite, Granite
- Passaic County: 42 sites; most recorded: Magnetite, Hematite
Top minerals
- Magnetite: 369 sites
- Limonite: 38 sites
- Hematite: 11 sites
- Chrysocolla: 8 sites
- Chalcocite: 7 sites
- Copper: 7 sites
- Granite: 5 sites
- Ilmenite: 4 sites
Mineral cards
Magnetite
Mohs 5.5–6.5. Black and strongly magnetic. Mindat
372 sites
Pyrite
Mohs 6–6.5. Brassy “fool’s gold,” often cubic. Mindat
46 sites
Mica
Mohs 2–3. Peels into thin, flexible, shiny sheets. Mindat
40 sites
Copper
Mohs 2.5–3. Native copper is soft and turns green as it weathers. Mindat
40 sites
Quartz
Mohs 7. Six-sided points; smoky quartz is NH’s state gem. Mindat
19 sites
Feldspar
Mohs 6–6.5. Blocky crystals with flat cleavage faces. Mindat
15 sites
Garnet
Mohs 6.5–7.5. Usually deep red, round many-faced crystals. Mindat
13 sites
Tourmaline
Mohs 7–7.5. Long striated crystals, often black (schorl) or green and pink (elbaite). Mindat
5 sites
Agate
Mohs 6.5–7. Banded, translucent chalcedony. Mindat
4 sites
Silver
Mohs 2.5–3. Native silver tarnishes black. Mindat
4 sites
Counts are sites whose USGS record mentions the mineral or commodity. Hardness from Mindat.
Minerals most often recorded
Magnetite 369Limonite 38Hematite 11Chrysocolla 8Chalcocite 7Copper 7Granite 5Ilmenite 4Cuprite 4Malachite 4Willemite 3Franklinite 3Counties
| County | Sites |
|---|---|
| Morris County | 331 |
| Warren County | 155 |
| Sussex County | 85 |
| Hunterdon County | 67 |
| Passaic County | 42 |
| Middlesex County | 19 |
| Somerset County | 16 |
| Ocean County | 12 |
| Union County | 10 |
| Essex County | 9 |
| Hudson County | 7 |
| Bergen County (fewer than 5 sites, no page) | 4 |
| Mercer County (fewer than 5 sites, no page) | 4 |
| Gloucester County (fewer than 5 sites, no page) | 2 |
| Camden County (fewer than 5 sites, no page) | 2 |
| Cumberland County (fewer than 5 sites, no page) | 1 |
| Cape May County (fewer than 5 sites, no page) | 1 |
Mineral guides
- Quartz in New Jersey (19)
- Garnet in New Jersey (13)
- Mica in New Jersey (40)
- Feldspar in New Jersey (15)
- Magnetite in New Jersey (372)
- Pyrite in New Jersey (46)
- Copper in New Jersey (40)
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