A continental collision about 1 billion years ago buried, heated and folded the layers of mineral-rich ore and marble, Verbeek said. Later exposed by glaciation and discovered by North Jersey early iron miners, the area’s iron-, zinc- and manganese-laced ore was commercially extracted until 1986.
The slab set for display was cut in late 2017 using a $6,000 diamond-studded cable laced through guide holes and powered by a generator. Initially due for presentation in 2019 as part of the $30 million renovation, the slab will sit in the 11,000-square-foot Allison and Roberto Mignone Halls of Gems and Minerals near other exhibits including:
The 632-carat Patricia Emerald