Hopewell: Calcite & Stilbite Rockhounding in Somerset County, New Jersey

Updated June 2026

Hopewell is a mapped rockhounding spot in Somerset County, New Jersey. Reported finds include calcite, stilbite, prehnite, malachite, chalcopyrite, and more. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Somerset County
State: New Jersey
Nearest road: Long Hill Road
Coordinates: 40.45779, -74.72069

Geology at Hopewell

This spot sits on Diabase, mapped as plutonic that formed roughly 200 to 145 million years ago. Plutonic rock like this weathers slowly into grus and boulders, and the most productive collecting is typically in weathered zones and drainages.

Mapped unit: Diabase
Age: 200–145 Ma (Jurassic)
Rock types: plutonic
Elevation: 520 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 Hopewell

Best months: March to November. Typical highs run 84°F in midsummer and 37°F in midwinter, with winter lows near 21°F.

Climate normals: NOAA 1991-2020 monthlies, WERTSVILLE 4 NE station (3 mi away), adjusted for elevation.

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 Hopewell

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 Hopewell.

Across the state line from Hopewell

Hopewell 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.

Hopewell FAQ

Where is Hopewell?+

Hopewell is in Somerset County, New Jersey, at 40.45779, -74.72069. Nearest road: Long Hill Road.

What rocks and minerals can you find at Hopewell?+

Hopewell is reported to produce Calcite, Stilbite, Prehnite, Malachite, Chalcopyrite, Copper.

Is collecting allowed at Hopewell?+

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 Hopewell?+

A rock hammer, gloves, and safety glasses are enough for oxidized copper ground. Look for green and blue staining on weathered rock and in old dump piles.

When is the best time to visit Hopewell?+

The most comfortable months at Hopewell are March to November.

How do I get to Hopewell?+

Open the directions link to navigate to 40.45779, -74.72069 in Google Maps. The nearest road is Long Hill Road.

More rockhounding in New Jersey

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Open Hopewell on the map

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