RockWoofBest regions by county
Ranked by the number of USGS-recorded sites, not by access or quality.
- Hardin County: 252 sites; most recorded: Fluorite, Galena, Sphalerite
- Jo Daviess County: 246 sites; most recorded: Sphalerite, Galena, Marcasite
- Pope County: 110 sites; most recorded: Fluorite, Galena, Sphalerite
- Alexander County: 21 sites
- Union County: 9 sites
Top minerals
- Fluorite: 136 sites
- Sphalerite: 76 sites
- Galena: 69 sites
- Barite: 9 sites
- Smithsonite: 4 sites
- Sand and Gravel: 3 sites
- Marcasite: 2 sites
- Chalcopyrite: 2 sites
Mineral cards
Fluorite
Mohs 4. Cubes in purple, green or yellow; many glow under UV. Mindat
357 sites
Galena
Mohs 2.5–2.75. Heavy, silvery lead ore that breaks into cubes. Mindat
90 sites
Quartz
Mohs 7. Six-sided points; smoky quartz is NH’s state gem. Mindat
54 sites
Pyrite
Mohs 6–6.5. Brassy “fool’s gold,” often cubic. Mindat
42 sites
Silver
Mohs 2.5–3. Native silver tarnishes black. Mindat
12 sites
Tourmaline
Mohs 7–7.5. Long striated crystals, often black (schorl) or green and pink (elbaite). Mindat
5 sites
Copper
Mohs 2.5–3. Native copper is soft and turns green as it weathers. Mindat
3 sites
Gold
Mohs 2.5–3. Soft, heavy and bright yellow; it doesn’t tarnish. Mindat
1 site
Counts are sites whose USGS record mentions the mineral or commodity. Hardness from Mindat.
Minerals most often recorded
Fluorite 136Sphalerite 76Galena 69Barite 9Smithsonite 4Sand and Gravel 3Marcasite 2Chalcopyrite 2Counties
| County | Sites |
|---|---|
| Hardin County | 252 |
| Jo Daviess County | 246 |
| Pope County | 110 |
| Alexander County | 21 |
| Union County | 9 |
| Saline County | 8 |
| Will County | 7 |
| LaSalle County | 5 |
| Jackson County (fewer than 5 sites, no page) | 4 |
| Madison County (fewer than 5 sites, no page) | 4 |
| Cook County (fewer than 5 sites, no page) | 4 |
| Massac County (fewer than 5 sites, no page) | 3 |
| Johnson County (fewer than 5 sites, no page) | 3 |
| St. Clair County (fewer than 5 sites, no page) | 3 |
| Gallatin County (fewer than 5 sites, no page) | 2 |
| Stephenson County (fewer than 5 sites, no page) | 2 |
| Macoupin County (fewer than 5 sites, no page) | 2 |
| Lake County (fewer than 5 sites, no page) | 2 |
| Bureau County (fewer than 5 sites, no page) | 2 |
| Pulaski County (fewer than 5 sites, no page) | 1 |
| Woodford County (fewer than 5 sites, no page) | 1 |
| Kane County (fewer than 5 sites, no page) | 1 |
| DuPage County (fewer than 5 sites, no page) | 1 |
| Montgomery County (fewer than 5 sites, no page) | 1 |
| Fayette County (fewer than 5 sites, no page) | 1 |
| Calhoun County (fewer than 5 sites, no page) | 1 |
| DeKalb County (fewer than 5 sites, no page) | 1 |
| Kankakee County (fewer than 5 sites, no page) | 1 |
| Grundy County (fewer than 5 sites, no page) | 1 |
| Christian County (fewer than 5 sites, no page) | 1 |
| Lawrence County (fewer than 5 sites, no page) | 1 |
| Henderson County (fewer than 5 sites, no page) | 1 |
Mineral guides
- Quartz in Illinois (54)
- Pyrite in Illinois (42)
- Galena in Illinois (90)
- Fluorite in Illinois (357)
- Silver in Illinois (12)
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