Franklin Furnace: Fluorite & Franklinite Rockhounding in Sussex County, New Jersey

Updated June 2026

Franklin Furnace is a mapped rockhounding spot in Sussex County, New Jersey. Reported finds include fluorite, franklinite, magnetite, tephroite, willemite, and more. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Sussex County
State: New Jersey
Nearest road: Buckwheat Road
Postcode: 07416
Coordinates: 41.11625, -74.58734

Geology at Franklin Furnace

This spot sits on Franklin Marble, mapped as marble that formed roughly 1600 to 1000 million years ago. Metamorphic terrain like this commonly hosts vein and replacement mineralization, and old workings typically mark the productive zones.

Mapped unit: Franklin Marble
Age: 1600–1000 Ma (Mesoproterozoic)
Rock types: marble
Elevation: 610 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 Franklin Furnace

Best months: March to November. Typical highs run 83°F in midsummer and 35°F in midwinter, with winter lows near 17°F.

Climate normals: NOAA 1991-2020 monthlies, SUSSEX AP station (6 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 Franklin Furnace

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 Franklin Furnace.

Across the state line from Franklin Furnace

Franklin Furnace 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.

Franklin Furnace FAQ

Where is Franklin Furnace?+

Franklin Furnace is in Sussex County, New Jersey, at 41.11625, -74.58734. Nearest road: Buckwheat Road.

What rocks and minerals can you find at Franklin Furnace?+

Franklin Furnace is reported to produce Fluorite, Franklinite, Magnetite, Tephroite, Willemite, Zincite.

Is collecting allowed at Franklin Furnace?+

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 Franklin Furnace?+

A rock hammer, gloves, and safety glasses cover old mining-district ground. Stay out of shafts and adits; the best specimens typically come from dump piles.

When is the best time to visit Franklin Furnace?+

The most comfortable months at Franklin Furnace are March to November.

How do I get to Franklin Furnace?+

Open the directions link to navigate to 41.11625, -74.58734 in Google Maps. The nearest road is Buckwheat Road.

More rockhounding in New Jersey

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Open Franklin Furnace on the map

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