Willowdale: Quartz Rockhounding in Chester County, Pennsylvania

Quick details

Access

Permission required

County

Chester County

State

Pennsylvania

Nearest road

North Mill Road

Postcode

19348

Coordinates

39.86605, -75.73520

Geology at Willowdale

This spot sits on Cockeysville Marble, mapped as marble that formed roughly 540 to 250 million years ago. Metamorphic terrain like this typically carries quartz veins and sweats, and weathered crystals tend to end up in the soils and streams below.

Mapped unit

Cockeysville Marble

Age

540–250 Ma (Paleozoic)

Rock types

marble

Elevation

320 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 Willowdale

Best months: March to November. Typical highs run 84°F in midsummer and 39°F in midwinter, with winter lows near 23°F.

Climate normals: NOAA 1991-2020 monthlies, AVONDALE 2 N station (3 mi away).

Land & collecting status

Permission required before collecting

Requires landowner or agency permission before any collecting. Do not enter without explicit authorization.

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 Willowdale

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

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