RockWoofSketch map
Woof’s favorite find
La Salle County Fire Clay
We picked it because its USGS record mentions 2 gem or collectible minerals (Tourmaline, Quartz) and 3 of our card minerals overall. No other named site here scores as high on both counts. USGS lists it as past producer. Minerals mentioned: Tourmaline, Quartz, Pyrite. Approx. location 41.419, -88.634. 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?
Was producing when the record was made.
A processing plant site.
Produced ore or material at some point in the past.
Status terms come from USGS MRDS records.
Mineral cards
Tourmaline
Mohs 7–7.5. Long striated crystals, often black (schorl) or green and pink (elbaite). Mindat
1 site
Quartz
Mohs 7. Six-sided points; smoky quartz is NH’s state gem. Mindat
1 site
Pyrite
Mohs 6–6.5. Brassy “fool’s gold,” often cubic. Mindat
1 site
Counts are sites whose USGS record mentions the mineral or commodity. Hardness from Mindat.
Minerals recorded here
No individual minerals are listed in these records.
Commodities
Silica 4Sites
| Site | Commodity | Minerals recorded | Status | Approx. location |
|---|---|---|---|---|
| La Salle County Fire Clay | — | — | Past Producer | 41.419, -88.634 |
| Ottawa Industries Sand Pit | Silica | — | Producer | 41.337, -88.882 |
| Manley Bros. Troy Grove Pit | Silica | — | Plant | 41.466, -89.073 |
| Serena Sand Plant-Zemi Corp. Pit | Silica | — | Producer | 41.460, -88.752 |
| Unimin Utica Plant & Pit | Silica | — | Plant | 41.353, -88.994 |
Nearby counties
Bureau County · Grundy County · DeKalb County · Kane County · Will County
Illinois mineral guides
Back to all Illinois 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 USGS ceased systematic updates to MRDS around 2011, so status and details may be out of date.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