Lambertville: Axinite & Tourmaline Rockhounding in Mercer County, New Jersey

Updated June 2026

Lambertville is a mapped rockhounding spot in Mercer County, New Jersey. Reported finds include axinite, tourmaline. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Mercer County
State: New Jersey
Nearest road: River Road
Postcode: 18977
Coordinates: 40.32359, -74.91196

Geology at Lambertville

This spot sits on Diabase, mapped as plutonic that formed roughly 200 to 145 million years ago. Granitic rock like this is where pegmatite pockets tend to occur, the coarse-crystal settings that typically carry beryl, tourmaline, mica, and feldspar.

Mapped unit: Diabase
Age: 200–145 Ma (Jurassic)
Rock types: plutonic
Elevation: 100 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 Lambertville

Best months: March to December. Typical highs run 88°F in midsummer and 41°F in midwinter, with winter lows near 19°F.

Climate normals: NOAA 1991-2020 monthlies, LAMBERTVILLE 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 Lambertville

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 Lambertville.

Across the state line from Lambertville

Lambertville 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.

Lambertville FAQ

Where is Lambertville?+

Lambertville is in Mercer County, New Jersey, at 40.32359, -74.91196. Nearest road: River Road.

What rocks and minerals can you find at Lambertville?+

Lambertville is reported to produce Axinite, Tourmaline.

Is collecting allowed at Lambertville?+

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 Lambertville?+

A rock hammer, a pry bar, gloves, and safety glasses suit pegmatite ground. Work weathered zones and check dump piles; coarse crystals often sit in decomposed rock.

When is the best time to visit Lambertville?+

The most comfortable months at Lambertville are March to December.

How do I get to Lambertville?+

Open the directions link to navigate to 40.32359, -74.91196 in Google Maps. The nearest road is River Road.

More rockhounding in New Jersey

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Open Lambertville on the map

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