RockHoundR

Rockhounding in New Jersey

Updated July 2026

72 mapped spots for rock hunting and rock collecting across 19 counties. New Jersey packs a lot into a small state: the Franklin and Sterling Hill zinc mines in Sussex County, the fluorescent mineral capital of the world, Cretaceous shark teeth and belemnites in the Monmouth County brooks, Cape May diamonds on the Delaware Bay beaches, amber from the Raritan clays, and prehnite and zeolites from the Watchung basalt quarries.

Where is the best rockhounding in New Jersey?

The best rockhounding in New Jersey is at Franklin in Sussex County (epidote, pyrite), Franklin-Ogdensburg-Sterling Hill mining district in Sussex County (willemite, zincite), and Shark River in Monmouth County (shark tooth, fossil). In total, 72 mapped collecting spots across 19 counties produce quartz, calcite, and amber, each listed below with its land access.

Open the full map

Every rockhounding spot in New Jersey

New Jersey rockhounding photos

Representative spot and material photos from locations in this state, shown where verified public image records are available.

5 photos

Top minerals found in New Jersey

Counts reflect how many spots in this list mention each mineral.

Notable areas: Franklin and Sterling Hill fluorescent minerals, Big Brook shark teeth, Paterson prehnite, Sayreville amber, and Cape May diamonds are the New Jersey targets collectors travel for.

Geology behind New Jersey rockhounding

The Highlands of Sussex, Passaic, and Morris counties are Precambrian gneiss and marble. The Franklin Marble hosts the Franklin and Sterling Hill zinc orebodies, whose franklinite, willemite, and zincite came with more than 350 other mineral species, many of them brilliantly fluorescent. The Newark Basin to the south is Triassic and Jurassic red sandstone cut by the Watchung basalt flows and the Palisades diabase sill, which carry prehnite, datolite, pectolite, and zeolites in quarries around Paterson, Prospect Park, and Bound Brook. Hunterdon County's Delaware River gravels carry agate, jasper, and quartz down from Pennsylvania. The Coastal Plain is Cretaceous and Eocene marl and sand: the Monmouth County brooks (Big Brook, Poricy, Ramanessin, Shark River) cut greensand that sheds shark teeth, belemnites, and mosasaur fragments, the Raritan Formation clays around Sayreville hold Cretaceous amber, and the Cape May beaches concentrate clear quartz pebbles known as Cape May diamonds.

Best regions to focus your search

Franklin and Sterling Hill (Sussex)

Sterling Hill Mining Museum in Ogdensburg and the Franklin Mineral Museum's Buckwheat Dump run fee collecting on their mine dumps; bring a UV lamp. The mines themselves are closed except by tour.

Monmouth County fossil brooks

Big Brook Park, Poricy Park, Ramanessin Brook, and Shark River yield Cretaceous and Eocene shark teeth, belemnites, and bone. The Monmouth County Park System allows hand collecting under posted rules: small hand tools, no digging into the banks, a modest per-visit take.

Watchung basalt quarries (Passaic, Somerset, Morris)

Prehnite, pectolite, datolite, and zeolites from quarries that open only on club days or by permission. The Paterson and Prospect Park quarries and Chimney Rock near Bound Brook are the famous names.

Cape May and the Delaware River (Cape May, Hunterdon, Gloucester)

Cape May diamonds at Sunset Beach and Higbee Beach, Delaware River gravel agate and jasper near Riegelsville, and Cretaceous marine fossils at the Edelman Fossil Park in Mantua on its public dig days.

Best season

Year-round for the brooks, best after heavy rain washes new material out of the banks and at low summer water. Sterling Hill and Franklin dump collecting runs spring through fall with special night digs for fluorescents. Cape May diamonds are best in winter and after storms.

What to bring

For the brooks a hand trowel, a small screen, and a zip bag; digging tools larger than a trowel are not allowed. For the mine dumps a rock hammer, safety glasses, gloves, and a shortwave UV lamp. For beaches a scoop and patience. Knee boots for everything.

Local collecting history

Franklin and Sterling Hill were mined for zinc from the 1700s until 1986 and are the type locality for dozens of minerals, which is why Franklin calls itself the fluorescent mineral capital of the world. Monmouth County's marl pits shipped greensand fertilizer in the 1800s and turned up the first North American dinosaur, Hadrosaurus, at Haddonfield in 1858.

Rockhounding near major New Jersey cities

Day-trip range. Each section lists the closest mapped rockhounding spots within about 150 miles of the city. Most are inside a 2 to 3 hour drive.

Neighboring states with rockhounding

Geology rarely respects state borders. These states share mapped rockhounding country with New Jersey, useful when New Jersey is the start, not the whole trip. Each card links to the closest county across the line.

Rockhounding by county in New Jersey

County pages are linked once we have at least 3 mapped spots for a focused guide with coordinates, mineral notes, and nearby spots.

Top picks in New Jersey

10 best spots

Hand-picked standouts from the New Jersey list, chosen for unusual mineralogy, documented public access, or both. Each card links to coordinates, access notes, and what to look for.

Rock and mineral clubs in New Jersey

6 clubs in New Jersey. Clubs run field trips, shows and workshops, and many trips go to private claims you can't reach alone.

Full club directory →

New Jersey rockhounding FAQ

Is rockhounding legal in New Jersey?+
Yes, at the Franklin and Sterling Hill fee dumps, in the Monmouth County fossil brooks under park rules, at the Edelman Fossil Park on public dig days, on quarry club days, and on private land with permission. State parks, state forests, and wildlife management areas prohibit collecting.
Where can I find shark teeth in New Jersey?+
Big Brook Park in Colts Neck, Poricy Park in Middletown, Ramanessin Brook in Holmdel, and Shark River in Neptune. Sift the gravel bars with a trowel and small screen; teeth, belemnites, and bone concentrate where the current slows. Follow the county park rules on tools and quantities.
Can I collect fluorescent minerals at Franklin?+
Yes. Sterling Hill Mining Museum runs fee collecting on its dumps, including scheduled night digs, and the Franklin Mineral Museum opens the Buckwheat Dump for a fee. Bring a shortwave UV lamp: willemite glows green, calcite red. The mines themselves are open only for tours.
What are Cape May diamonds and where do I find them?+
Clear quartz pebbles tumbled smooth by the Delaware River and concentrated on the Delaware Bay beaches at Cape May Point, especially Sunset Beach and Higbee Beach. They are surface picks, best in winter and after storms; no digging is allowed on the dunes.
What rocks and minerals can you find in New Jersey?+
New Jersey spots in this list most often produce amber, agate, quartz, amethyst, calcite, banded agate, albite, and fossils, plus fluorescent willemite and calcite at Franklin, prehnite and zeolites from the basalt quarries, and Cretaceous shark teeth.
Where can I go rock hunting in New Jersey?+
Rock hunting, rock collecting and rockhounding are the same hobby under different names. 72 spots are mapped in New Jersey, 66 of them with public access. Morris County, Somerset County, and Monmouth County have the most.
Is there gem mining or pay-to-dig in New Jersey?+
No fee digs or pay-to-dig gem mines are mapped in New Jersey yet. 66 of the 72 spots here have public access, so you can collect without paying a dig fee.
Where can I dig for crystals in New Jersey?+
24 mapped spots in New Jersey report quartz, amethyst, or smoky quartz, mostly in Somerset County, Hudson County, and Bergen County. Each one is in the list on this page with its land access.
Can you find geodes in New Jersey?+
Yes. 1 mapped spot in New Jersey reports geodes, mostly in Somerset County.
Where can I go fossil hunting in New Jersey?+
7 mapped spots in New Jersey report fossils, mostly in Monmouth County and Gloucester County. On federal land you may keep common shells, corals and plant fossils. Bones and teeth of animals with a backbone are protected.

Map every New Jersey spot in the app

Open the RockHoundR app to see New Jersey on a real map with public land overlays, weather, geology, and your saved finds.

Download on the App StoreGet it on Google Play