New Jersey mining: Rare minerals to set American Museum of Natural History display aglow

David M. Zimmer
NorthJersey
A 19-by-9 foot slab of fluorescent rock was cut from a pit mine in Ogdensburg, N.J.'s Sterling Hill complex in late 2017. The slab is due to be displayed in New York City's American Museum of Natural History in 2019.

North Jersey's rich mining history is about to make — well, more history. 

A slab of flourescent rock shorn from the side of a dormant pit mine in New Jersey's northern Highlands will be on display in the American Museum of Natural History.

The rock measures 19 feet by 9 feet and looks unassuming in daylight, despite weighing nearly 22 tons in its four separate pieces. Washed in ultraviolet light, however, the rock's brilliance comes alive. The rare minerals it contains fluoresce neon shades of red and green. 

"A lot of museums have beautiful specimens, maybe the size of a turkey," said William Kroth, president of the Sterling Hill Mining Museum in Ogdensburg where the rock was extracted late last year. "This will truly be a wonder of the world."

Plans are to encase the rock as one continuous panel in the American Museum of Natural History in 2019 as part of a $30 million renovation to create the new Mignone Halls of Gems and Minerals, museum officials say. Once thinned and polished, the rock face previously preserved under 38 feet of rock and soil, is due to be bathed in 20 ultraviolet lights.

The rare renewal of mining at the Sterling Hill site late last year took about 150 minutes. The process used a $6,000 diamond-studded cable laced through three pre-drilled guide holes and powered by a generator, which had to be brought in from Connecticut, Kroth said.

A 19-by-9 foot slab of fluorescent rock was cut from a pit mine in Ogdensburg, N.J.'s Sterling Hill complex in late 2017. The slab is due to be displayed in New York City's American Museum of Natural History in 2019.

The modern mining technique provided a stark contrast to records of New Jersey settlers picking lumps of bog iron from the swampland of Tinton Falls in the 1650s. The technique was removed still from the explosive-centric method used by miners three centuries later to chase metal-laced minerals in the state's northern Highlands, Kroth said.

In some places, New Jersey's now-abandoned mines are historic landmarks, with groomed trails snaking among foundations, furnaces, and fenced-in shafts. In other places, the signs are less visible: mounds of waste rock covered in brush, sunken depressions holding water, and tunnels that thread under communities built upon the ground that shaped them.

The Sterling Hill Mining Museum in Ogdenburg, as seen on Oct. 17, 2017, operates in and around one of the world's most famous zinc mines.

"If you're going to mine anything, you really have to build a town around that mine," said Ronald Mishkin, a retired geologist who worked in three of North Jersey's last working iron mines.

Nearly 92 percent of the state's 588 abandoned mines collected iron, state records show. The vast majority of those mines tapped deposits that run southwest through the state's northwest corner. Two of the most famous, the twin mine of Franklin and Ogdensburg, primarily mined zinc encased in folds of white marble. 

Mishkin, now 86, started his mining career in Franklin, a planned community shaped by the New Jersey Zinc Company. 

The zinc company was founded in 1852 and quickly built smelting plants in Newark, Passaic, and Bergen Point. However, it did not take off until 1897, when it brought an end to local claim disputes by consolidating about 20 area mines. Within 16 years, the zinc company would help expand the population of Franklin six-fold and become Sussex County’s largest employer, local records show.

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Map of New Jersey's mines

Many of the employees were immigrants scouted from Poland, Russia, and the Slavic nations, Mishkin said. The company offered them jobs and strongly suggested they buy company-built bungalows replete with backyard gardens, Mishkin said. 

The homes were $1,500 to $2,000; rent to own. Workers were escorted directly to town from Ellis Island, he said.

A collection of drills lines the wall of an adit in the Sterling Hill Mine on Oct. 17, 2017.

In Franklin, Russians lived in Siberia. In Odgensburg, Hungarians had Hunk Town. As an intern more than 60 years ago, Mishkin lived "high on the hog" in a boarding house. There, he received maid service and three meals a day for just $58 a month.

"The different ethnic groups all had their own communities, but they made friends. They bonded over mining," he said. "Nobody gave a damn if you were Hungarian or Russian."

What was lacking in discrimination, Mishkin said, was made up for in pranks: nailing a lunch bucket to a board or swapping out a ham sandwich with industrial grease on white. Mishkin's mother-in-law also buried his father-in-law's mineral collection under the path of what hours later became a Siberia sidewalk.

A tour guide at the Sterling Hill Mining Museum leads a group through the former zinc mine on Oct. 17, 2017.

Before closing in 1986 due to adverse market conditions, the zinc mines of Franklin and Ogdensburg combined to produce 33 million tons of ore, records show.

A massive mine shaft at Sterling Hill carried everything from ore to people to and from depths of roughly 1,900 feet.

The extraction process conceived by Robert Catlin, the zinc company's mine superintendent, in the early 1900s was remarkably efficient, Mishkin said.

Ore blocks containing more than 20 percent zinc were mapped, extracted, and repacked level by level to ensure the stability of the mine structure, he said. Magnets and other machinery helped separate the zinc from ore containing iron and manganese.

Franklin zinc was first used commercially in 1838, when it was featured in America's first standard set of brass weights and measures. It became such a valuable component for brass shell casings during World War II that the hills of Franklin and Ogdensburg were guarded by the U.S. military.

The red arch in the Rainbow Room at the Sterling Hill Mining Museum, as seen on Oct. 17, 2017, appears to have a skull shape at its apex.

Today, the meticulously blasted tunnels in Odgensburg serve as a monument to mining. About 10 groups of grade school students flock to the Sterling Hill Mining Museum every school day to explore the most well-preserved of all the state's mines on guided tours.

Mine walls carved in weeping Franklin marble, the state's largest known flowstone, and, yes, glowing minerals mark the experience.  

Frankly, no one cares about the zinc. 

"Here's what they care about: We're the world's premier location for the most beautiful fluorescing minerals," Kroth said. "We are a wonder of the world, and I don't use that term lightly."

Nearly 90 minerals found in the area are fluorescent and display bright colors under ultraviolet light, Mishkin said. Some even phosphoresce after the blacklights go out.

"There's no place else like this on the planet, and it's not even close," Kroth said.

The most famous rocks at the Sterling Hill Mining Museum are the ones that fluoresce. A case containing a variety of the stones, many of which are found in the area, is illuminated on Oct. 17, 2017.

The region's geology started taking shape about 1.3 billion years ago, said Earl Verbeek, a former research geologist with the U.S. Geological Survey and the curator of the Franklin Mineral Museum.

The metals that define the area's ore were spread by geothermal vents fed by fracture zones under a muddy and shallow sea floor, similar to the Bahama Banks, which became the ore's marble cocoon, Verbeek said. 

Cases filled with specimen rocks line the Sterling Hill Mining Museum on Oct. 17, 2017.

"You had a very fine rain of metalliferous particles falling down on the sea floor and that gave you very metal-rich layers inter-layered with the sediments that were accumulating at that time," Verbeek said. 

Those layers were buried, heated, and folded during a continental collision about 300 million years later, Verbeek said. The resulting features form the base rock of the Highlands and the minerals within that were later exposed by periods of glaciation, he said. 

At last count, 372 different minerals have been found in and around the twin mines in Franklin and Ogdensburg, Verbeek said. Of those minerals, 19 have been found nowhere else on earth, he added. 

"There aren't too many chunks of ground that are more complicated than what we see places that have anywhere near that complexity," Verbeek said of the two-square mile zone in Sussex County. "We're certainly in the top five." 

Fossils sit below hanging lunch buckets and baskets at the Sterling Hill Mining Museum on Oct. 17, 2017.

The complexity of the area's iron-, zinc- and manganese-laced ore, which was initially and erroneously thought to contain copper, required the invention of a new separating procedure to extract the zinc in 1852, Mishkin said. During the following two years, the mine complex was the only one in the nation producing zinc, records show.

For the next 110 years no one knew - and few cared - how the area's ore was formed, Verbeek said. Almost all of the earth's zinc has been found in and around sulfides, Mishkin. That is not so in the twin mines of Sussex County. 

"I could study those deposits for the rest of my life and never will I have the chance to say, 'OK, now I understand it. There's nothing left to do. What's next?'" Verbeek said.

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A wall of iron stained rock sits above a shallow pool in the Edison Mine area in Ogdensburg on Oct. 17, 2017.

The dual zinc mines were the last of New Jersey's mines to close. Similar to the hundreds of iron mines in the region, however, the mines were not abandoned due to a lack of elements or minerals, Mishkin said.  

"There may be 600 million tons of iron ore left around here," he said. “There is plenty of ore. The problem is getting it out.” 

The Hurd Mine in Jefferson Township, N.J., seen on Oct. 17, 2017, sits next to a highway covered in rock and hidden by trees.

In the early days, mining in the Highlands was simple, said Kroth. The often-magnetic ore poked right up through the surface in outcrops anyone could walk right up to and chisel on, Mishkin said.

The further the ore dipped, often at angles of about 30 degrees, the more complicated and dangerous the work became, Mishkin said. Pits were dug. Blobs were mined. Eventually, tunnels and shafts were constructed to case veins. 

Underground mining started in the Highlands in about 1710 at the Mount Hope iron mine near Dover, records show. By the mid-1800s, the region was effectively the iron smelting capital of the United States, Mishkin said.

The Township of Jefferson alone had 19 mines, including the Hurd(town) Mine.

The Hurd Mine in Jefferson Township was once the deepest in New Jersey. The mine, seen on Oct. 17, 2017, is now covered by waste rock that provides the only hint of its past.

Now marked by piles of blasted granite, cloaked by hardwoods and encircled by off- and on-ramps, the iron mine opened in 1855. For 20 years, the mine was cut by hand, Mishkin said.

Men working solo or in pairs would chisel about three feet of tunnel every five days, Mishkin said. The introduction of dynamite and steam-powered, dust-spewing dry drills in the 1870s sped up the process, he added. By the time it closed in 1898, the Hurd Mine was the deepest in the state.

The mine's bottom slope measured 6,000 feet long and dipped 2,600 feet below the surface, state records show. Today, it sits completely out of sight near mile seven of Route 15, where overpass construction was once complicated by concrete-swallowing tunnels.

“There were 450 iron mines operating in New Jersey in the 1880s. By the year 1900, there were 20,” Mishkin said.

A narrow shaft in the Edison Mine area in Ogdensburg on Oct. 17, 2017 shows the small size of some of the region's iron ore veins.

By the turn of the 20th century, the region's deep and narrow skinny ore veins had become needlessly difficult to mine, Mishkin said.  

A grizzly, a grate that catches larger rocks from going into the mine cars below, sits above a pool in the Sterling Mine on Oct. 17, 2017.

The recently-opened Mesabi Range in Michigan and Minnesota offered such volume that it could undercut Edison's iron prices by 50 percent, Mishkin said. The ore bed there is 100-miles long and several miles wide in places, according to U.S. Geological Survey records. The iron is also close to the surface and easy to extract, Mishkin said. 

"The Mesabi Range is responsible for putting just about everything out of business here,” Mishkin said. "About 75 percent of all the iron used in America came from there." 

New Jersey had one last dabble in iron mining in 1977, when the Mount Hope Mine reopened for one year. Near Dover, the mine was one of the richest and most productive iron mines in the state, records show.

A variety of signs line the walls of the lantern room in the Sterling Mine, as seen on Oct. 17, 2017.

The gamble to reopen Mount Hope as the only iron mine east of the Mississippi was spurred by government subsidies and slowing iron production elsewhere, Mishkin said.

"They needed everything to go just right," Mishkin said. "It didn't."

Iron mining in New Jersey had effectively come to an end in 1966, when Mishkin helped pull some of the last ore out of Scrub Oaks. Scrub Oaks stretched from Mine Hill near Route 46 to Wharton, was 3,000-feet deep, and at its peak produced 200,000 tons of ore a year, state records show.  

The Ogden Rail Bed Trail was first laid as a way for Thomas Edison to get Iron Ore to market from Ogdensburg. Abandoned when higher grade ore elsewhere put the mine out of business, the property ended up in the possession of the Morris County Parks Commission and was converted into a hiking trail.

Though long gone, New Jersey's iron industry undoubtedly left its mark on the region. Mining operations would consume as much as an acre a day of forest to feed the furnaces with charcoal to produce pig iron, named for the shape of the molds used to capture molten iron flowing from the furnaces. 

“About 1885 or ’90, the whole of Sussex County, Morris, and Passaic looked like the Gobi Desert,” Mishkin said. “They cut all the trees down.” 

Discoveries of vast coal deposits in Pennsylvania slowed the deforestation but demanded more terraforming in the form of the 100-mile Morris Canal.

Joe Macasek, president of the Canal Society of New Jersey, in the 150-year-old tailrace tunnel that carried the water used to turn the turbine that powered the inclined plane at Plane 2 East in Ledgewood.

Hand-dug by immigrant workers in the late 1820s, the canal used lakes, locks, and inclined planes to transport cargo boats between newly formed canal towns. The main cargo was iron ore destined for transport to coal-fired furnaces in Pennsylvania towns such as Philipsburg, Allentown, and Palmerton, which was named after a former New Jersey Zinc Company president.

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The benefits of coal, the canal, and expanding rail system were a boon to the Hiberina mines in and around the north end of Rockaway Township, Mishkin said. Built in an ore bed estimated to be about two miles long, Rockaway hosted independent mines as early as 1722.

Mining failed to progress from low scale operations, however, until a group of miners joined forces in 1863 to build a railroad to the Morris Canal, state records show. Roughly 4.3-miles long, the railroad to Rockaway reignited the mine.  

Nine years later, another group combined to construct a mile-long underground tunnel. Production maxed out at 700 percent over the pre-railway days, state records show.

The mine held on longer than most but closed in 1913. And bats took over.

Little brown bats have made a former mine in Rockaway, N.J. an ideal home.

"A lot of [the mines] are now closed off, flooded, collapsed, or just don’t have the right conditions for bats," said MacKenzie Hall, a biologist with the New Jersey Division of Fish and Wildlife. "But a handful of them are really great for bats."  

At one point, 30,000 bats called Hibernia mines home, making it the largest known bat habitat in the state, Hall said.

Little brown bats have made a former mine in Rockaway, N.J. an ideal home.

The year-round, cool temperatures in many of the region's underground mines are ideal for New Jersey's six hibernating species of bats, she said. But they also safeguard a fungus that leads to white-nose syndrome, a disease that affects bats' senses and triggers self-destructive behaviors.

Now in 31 states, the fungus was first found in New Jersey in 2009. Within a few years, it had cut the state's little brown bat population by 99-percent, Hall said. Few bats remain. However, those that do are showing a nearly normal survival rate, which may hint to a genetic resistance to the fungus, Hall said. 

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"Other research shows that bats may be coping by fattening up more before winter, and by hibernating in cooler places where the white-nose fungus doesn’t grow as well," she said.  

The little brown bats that persist often keep to locations such as the Hibernia mines, a couple old tunnels in Sparta and other abandoned mine sites, Hall said. There, they hang on to a history mostly out of sight. 

Staff Writer Jai Agnish contributed to this article.