NJ 220px-Map of USA NJ

Rockhounding New Jersey

New Jersey is a good state for rockhounding.  Although there are numerous states with substantial dinosaur fossils, New Jersey is the state where – shortly before the Civil War – the first nearly complete dinosaur skeleton was found.  New Jersey also is home to the famous mineral deposits (and legacy mines) at Franklin and Sterling Hill.  This small locality has produced an astonishing number and variety of minerals.


State Rocks, Gemstones, Minerals, Fossils, & Dinosaurs

Rockhounding Tip:  Knowing state rocks, gemstones, minerals, fossils, and dinosaurs often can be very useful information for rockhounders.  Ordinarily, states with significant mineral deposits, valuable gemstones, fossils, or unusual or significant rock occurrences will designate an official state mineral, rock/stone, gemstone, fossil, or dinosaur to promote interest in the state’s natural resources, history, tourism, etc.  Accordingly, such state symbols often are a valuable clue as to potential worthwhile rockhounding opportunities.

New Jersey - Dino - Hadrosaur (first mounted skeleton)

Hadrosaurus (the first mounted skeleton)

State Dinosaur:  Hadrosaurus foulkii (1991)

New Jersey designated Hadrosaurus foulkii as its official state dinosaur in 1991.  Hadrosaurus foulkii was a duck-billed dinosaur.  The Hadrosaurus foulkii, the first nearly complete dinosaur skeleton to be discovered virtually intact anywhere in the world, was unearthed in October, 1858, in a marl pit in Haddonfield, Camden County, by William Parker Foulke, a member of the prestigious Academy of Natural Sciences of Philadelphia.  This discovery of a 25-foot, eight-ton, duck-billed, herbivorous saurian (or reptile), which stood as high as ten feet at the hips, was so unexpected and unusual that it startled the scientific thinking of the day and led to a revision of many conventional ideas as to the physical structure and life habits of prehistoric reptiles and provided a great stimulus to the study of dinosaurs which, until then, were relatively unknown outside the scientific community.  This dinosaur, which lived 100 to 70 million years ago during the Cretaceous period and which was given the name Hadrosaurus foulkii in honor of its discoverer, was the first dinosaur to be displayed for public view.


Rockhounding Resources

State-specific rockhounding books (including the books listed here as well as other books), regional rockhounding site guides, and other helpful rockhounding resources are identified - by category - in the Books & Gear section of Gator Girl Rocks with a link to the Gator Girl Rocks Amazon Store where you may easily browse selected resources and securely place an order.  Your order will benefit Charity Rocks!

Geological Survey logo - NJ

New Jersey Geological Survey


NJ Paleo Society

New Jersey Paleontological Society


  • Scott Stepanski & Karenne Snow, Gem Trails of Pennsylvania & New Jersey (Rev. ed. 2000).
  • Robert Beard, Rockhounding Pennsylvania & New Jersey (2013).
  • William B. Gallagher, When Dinosaurs Roamed New Jersey (1997).
  • Floyd & Helga Oles, Eastern Gem Trails (1967).
  • Allan W. Eckert, Earth Treasures Vol. 1 - Northeastern Quadrant (1985; reprint in 2000).
  • James Martin Monaco & Jeannette Hathway Monaco, Fee Mining & Mineral Adventures in the Eastern U.S. (2d ed. 2010).
  • Kathy J. Rygle & Stephen F. Pedersen, Northeast Treasure Hunter's Gem & Mineral Guide (4th ed. 2008).



Museums of Interest to Rockhounders

Museum - Sterling Hill MIning Museum

Sterling Hill Mining Museum
Ogdensburg, New Jersey
The Sterling Hill Mining Museum is a geology and mining museum located at the former Sterling Hill zinc & iron mine (closed in 1986).  The museum exhibits more than 20,000 mining-related items, including equipment used for explosives, moving and crushing ore, mine ventilation, mine lighting, and laboratory study of the ores.  Also featured are displays of the local fluorescent minerals, and large mineral samples out in the open, that are meant to be touched.


Museum - Franklin Hill Museum

Franklin Mineral Museum
Franklin, New Jersey
The Franklin Mineral Museum is a geology and mining museum located at the former Franklin Mine.  The mine was active from 1898 until the mid 1950s.  It became a museum on June 2, 1964.  In addition to a simulated mine, the museum has a large collection of minerals including one of the world's finest permanent exhibits of fluorescent minerals.  The display is over sixty feet long, eight feet high, and is lit with multiple high-power short-wave ultraviolet lamps and includes some of the best samples of willemite, calcite, hardystonite, esperite and other less common fluorescent minerals found in the Franklin-Sterling Hill area.


Museum - NJ State Museum logo

New Jersey State Museum
Trenton, New Jersey
The museum’s natural history collections include industrial minerals and ores and paleontology specimens.  The museum displays an early reconstruction of the first nearly complete dinosaur ever excavated, Hadrosaurus foulkii, which was found in Haddonfield, New Jersey in 1858.  The museum also is the repository for about 300 type (first documented) specimens of Paleozoic and Mesozoic fossils as well as a large number of fossils documenting the Paleozoic strata within the Delaware Water Gap National Recreation Area.  Minerals from the zinc-mining locality of Franklin-Sterling Hill are well represented, including the largest number of fluorescent mineral species in the world, as are mine-specific specimens from New Jersey’s industrial iron mining past.  Specimens from beyond New Jersey are used for comparative purposes in exhibitions.


Morris Museum
Morristown, New Jersey
The museum’s geological collection, considered one of the best in New Jersey, is home to numerous specimens from throughout the world, but has a focus on the state’s own mineralogical profile.  The geological collection represents 100 percent of New Jersey’s minerals, including Franklin and Watchung Mountain materials.


Rutgers University Geology Museum
New Brunswick, New Jersey
The Rutgers University Geology Museum includes a dinosaur trackway, a mounted mastodon from Salem County, New Jersey (found in 1869), rocks and minerals from New Jersey and around the world, and florescent minerals.


Meadowlands Museum
Rutherford, New Jersey
The museum has a changing display of rocks and minerals of New Jersey.


Places to Visit - Interesting Sites To See

Site- Haddonfield - where first dino was discovered in US

First Nearly Complete Dinosaur Discovery in the United States
Haddonfield, New Jersey
In the summer of 1858, fossil hobbyist William Parker Foulke was vacationing in Haddonfield, New Jersey, when he heard that twenty years previous, workers had found gigantic bones in a local marl pit.  Foulke spent the late summer and fall directing a crew of hired diggers shin deep in gray slime.  Eventually he found the fossilized bones of an animal larger than an elephant with structural features of both a lizard and a bird.  Foulke had discovered the first nearly complete skeleton of a dinosaur (Hadrosaurus foulkii).  Today, this site is a National Historical Landmark.


Rockhounding Sites for Children & Families

Museum - Franklin Hill Museum Sign

Franklin Mineral Museum
Franklin, New Jersey
In addition to the museum, visitors may collect specimens at the museum's collecting areas.


Specimen - Cape May diamonds

‘Cape May Diamonds’ – Quartz
Cape Point May, New Jersey
Cape May Diamonds are quartz crystals that originate in the Delaware Water Gap, a mountainous region where New Jersey, Pennsylvania and Delaware meet.  The crystals erode out of the mountains and wash into the Delaware River.  As the crystals are carried 200 miles to Cape May, the rough edges are warn and the clear surface becomes scratched, transforming the crystal into an opaque little pebble, literally a "diamond in the rough."  The stones can be found at Higbee and Sunset Beaches in Cape May.

Site - Poricy Park Fossil Beds copy

Fossils – Cretaceous Period
Poricy Brook Fossil Beds - Middletown, New Jersey
The Poricy Brook Fossil Beds are well known to fossil collectors in the Northeast.  The fossils are from the Cretaceous period of the Mesozoic era, 145 to 65 million years ago.  During the Cretaceous period, the area of Poricy Brook and the rest of the Atlantic Coastal Plain was a shallow ocean.  When the ocean animals died, they were buried in the bottom.  While their soft parts decayed, the harder parts (bones, teeth, and shells) were preserved.  Over millions of years, the ocean level rose and fell to form different layers of deposits with the remains of different animals.  The layer exposed by the cutting action of Poricy Brook is called the Navesink Formation and is approximately 72 million years old.  Although fossils of many animals have been found in the Poricy Brook Fossil Beds, most are of shellfish.  Visitors may collect up to five fossils.

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