RockHoundR
Back to map

Hamilton Quarry: Geode Digging in Hancock County, Illinois

Public access4 mineralsHancock County, IllinoisUpdated June 2026
Minerals reported
4
Elevation
390 ft
Best months
March to November

Hamilton Quarry is a mapped rockhounding spot in Hancock County, Illinois. Reported finds include geode, pyrite, calcite, sphalerite. Below: coordinates, access notes, nearby spots, and trip-planning links.

Plan your visit

Generally open to casual rockhounding

Nearest road
South 2nd Street
Postcode
62341
Get directionsView on Google Maps

Coordinates are approximate. Confirm the exact ground in the RockHoundR app, where land overlays show which agency manages the area.

Land & collecting status

Generally open to casual rockhounding

Most public-tagged spots sit on BLM, U.S. Forest Service, or other federal land where reasonable hand collecting of common rocks and minerals is allowed. Confirm posted rules and active mining claims before you dig.

Public-land rules vary by agency, season, and field office. The RockHoundR app pulls live BLM, USFS, NPS, and tribal overlays so you can see exactly which agency manages the ground at this spot.

Best time to visit Hamilton Quarry

Comfortable months (45 to 90°F highs)

Best months: March to November. Typical highs run 86°F in midsummer and 33°F in midwinter, with winter lows near 17°F.

Climate normals: NOAA 1991-2020 monthlies, KEOKUK L&D 19 station (1 mi away).

Geology at Hamilton Quarry

This spot sits on Warsaw Formation and Salem Limestone, mapped as limestone that formed roughly 345 to 330 million years ago. Limestone country like this is classic geode ground: cavities in the carbonate rock can line themselves with quartz or calcite crystals.

Mapped unit
Warsaw Formation and Salem Limestone
Age
345–330 Ma (Mississippian)
Rock types
limestone
Elevation
390 ft

Geologic mapping via Macrostrat and the underlying state geological survey maps (CC BY 4.0). Bedrock at the surface can vary within a mapped unit.

Today's weather

Is today a good day to go?

The app shows live weather, recent rain, and a daily rockhounding score for Hamilton Quarry.

Get the app

Sources & verification

Spot details combine the public RockHoundR location dataset, normalized mineral labels, agency land-status checks in the app, and community submissions. Coordinates are approximate until verified in the field.

Found at Hamilton Quarry

Each name opens all spots that produce that material; the encyclopedia link opens the full ID and field guide.

Nearby rockhounding spots

Other rockhounding spots within driving distance of Hamilton Quarry.

Across the state line from Hamilton Quarry

Hamilton Quarry is close enough to the Illinois border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.

Hamilton Quarry FAQ

Where is Hamilton Quarry?+
Hamilton Quarry is in Hancock County, Illinois, at 40.38220, -91.35544. Nearest road: South 2nd Street.
What rocks and minerals can you find at Hamilton Quarry?+
Hamilton Quarry is reported to produce Geode, Pyrite, Calcite, Sphalerite.
Is collecting allowed at Hamilton Quarry?+
Generally open to casual rockhounding. Most public-tagged spots sit on BLM, U.S. Forest Service, or other federal land where reasonable hand collecting of common rocks and minerals is allowed. Confirm posted rules and active mining claims before you dig. Always confirm current rules with the managing agency before a trip.
What tools should I bring to Hamilton Quarry?+
Bring a crack hammer, a chisel, safety glasses, and a bucket. Candidates are rounder and lighter than solid rock; a soil pipe cutter opens them cleaner than a flat smash.
When is the best time to visit Hamilton Quarry?+
The most comfortable months at Hamilton Quarry are March to November.
How do I get to Hamilton Quarry?+
Open the directions link to navigate to 40.38220, -91.35544 in Google Maps. The nearest road is South 2nd Street.

More rockhounding in Illinois

See all 31 Illinois spots →

Open Hamilton Quarry on the map

Use the RockHoundR app for live land overlays, weather, geology, directions, and saved finds.

Download on the App StoreGet it on Google Play
QR code that opens RockHoundR in your phone's app store
Get directionsDirections