Phillipsburg: Serpentine & Soapstone Rockhounding in Warren County, New Jersey

Updated June 2026

Phillipsburg is a mapped rockhounding spot in Warren County, New Jersey. Reported finds include serpentine, soapstone. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Warren County
State: New Jersey
Nearest road: River Road
Postcode: 18042
Coordinates: 40.64726, -75.19001

Geology at Phillipsburg

This spot sits on Allentown Dolomite, mapped as dolostone that formed roughly 495 to 470 million years ago. Carbonate rock like this dissolves and weathers readily, so fresh road cuts, quarries, and creek exposures are typically the most productive ground.

Mapped unit: Allentown Dolomite
Age: 495–470 Ma (Furongian to Early Ordovician)
Rock types: dolostone
Elevation: 190 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 Phillipsburg

Best months: March to November. Typical highs run 86°F in midsummer and 38°F in midwinter, with winter lows near 22°F.

Climate normals: NOAA 1991-2020 monthlies, PHILLIPSBURG-EASTON BRG station (3 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 Phillipsburg

Each chip 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 Phillipsburg.

Across the state line from Phillipsburg

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

Phillipsburg FAQ

Where is Phillipsburg?+

Phillipsburg is in Warren County, New Jersey, at 40.64726, -75.19001. Nearest road: River Road.

What rocks and minerals can you find at Phillipsburg?+

Phillipsburg is reported to produce Serpentine, Soapstone.

Is collecting allowed at Phillipsburg?+

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 Phillipsburg?+

A rock hammer, sturdy gloves, safety glasses, and a collecting bag cover the basics here. Add a spray bottle: wet rock shows color and pattern that dry rock hides.

When is the best time to visit Phillipsburg?+

The most comfortable months at Phillipsburg are March to November.

How do I get to Phillipsburg?+

Open the directions link to navigate to 40.64726, -75.19001 in Google Maps. The nearest road is River Road.

More rockhounding in New Jersey

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Open Phillipsburg on the map

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