Edwards County: Siderite Rockhounding in Edwards County, Illinois

Quick details

Access

Public area

County

Edwards County

State

Illinois

Nearest road

300E

Coordinates

38.42994, -88.09931

Geology at Edwards County

This spot sits on Mattoon Formation, mapped as shale that formed about 305 million years ago. Sedimentary rock like this erodes unevenly, so the most productive collecting is typically along fresh cuts, badland slopes, and active drainages.

Mapped unit

Mattoon Formation

Age

305–305 Ma (Pennsylvanian)

Rock types

shale

Elevation

430 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.

Best time to visit Edwards County

Best months: February to November. Typical highs run 90°F in midsummer and 40°F in midwinter, with winter lows near 24°F.

Climate normals: NOAA 1991-2020 monthlies, ALBION station (4 mi away).

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.

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.

Sources: RockHoundR public spot dataset, app land overlays, and local agency review before each trip.

Found at Edwards County

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

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