New York Rock and Minerals

Not all of New York is equally endowed with gem grade rocks and minerals.

But mining occurs in every county in New York State except Bronx, Kings, New York, Queens and Richmond.

More than half of New York is a plateau sweeping down from the Adirondacks in the northeast and underlain by very old sedimentary rocks. The Adirondacks, however, are formed of crystalline rocks and the best place to rockhound in the quarries, old mines, and streambeds.

The central plateau rises from Lake Erie and Lake Ontario, becoming mountains in the south and east, where the Appalachians enter the state, and where the plateau has been carved into the Catskill Mountains.

The topography of lower New York is like that of New Jersey, except that Long Island is a part of the coastal plain and consist of rocks left behind when the glaciers melted.

New York has lots of minerals which are mined for industrial and construction uses. Sand and gravel mines are found throughout the state. Metal ores and minerals are mined in the mountain regions. Salt is extracted from rich deposits in central New York.

Iron ore mining spread up the Hudson Valley and into the North Country and westward through the Mohawk Valley to western New York. Many more mines were established in regions such as the Hudson Highlands and Adirondacks than in the Catskills or Southern Tier. At the time of the Civil War, iron from the Adirondacks constituted twenty-five percent of the nation’s production and was critical to the war effort. All the iron ore mines were closed by 1982 and neither iron or titanium were being mined in New York by the beginning of the twenty-first century. The last of the gypsum mines closed in 1999. Mines for sphalerite, a primary zinc ore, were established in 1920 and continued to operate in St. Lawrence County until 2008.

Garnet was named the state mineral in 1969. Garnets are found mainly in the Hartland Formation and Manhattan Schist. Barton Mines in the Adirondacks is the largest garnet mine in the world.

Volcanic and sedimentary rocks in the Newark Basin are a prominent fossil-bearing feature near New York City from the Mesozoic rifting of the supercontinent Pangea.

Ancram County is just west of the Connecticut border and has a nice variety of ores. The best locations in this area are old mines and gravel pits. Pyrite, sphalerite, and barite are found in this region. In western upstate New York you can find pyrite and quartz crystals. Labradorite has been found near Cascades Lake and Candice Lake and on Owl’s Head Mountain Trail, located just a few miles south of Montreal, Canada. Buttermilk Falls State Park offers a range of minerals for rockhounders, like calcite, pyrite, quartz, and serpentine.

Perhaps the most famous rock found in New York is the Herkimer Diamond. The Herkimer Diamonds, found in western New York in Herkimer County, and the Mohawk River Valley, are not genuine diamonds, they are double-terminated quartz crystals that form in vugs of the Little Falls dolomite. There is a Pay to Dig for these beautiful crystals usually open sometime in April to October.

Before venturing out-do some research on where and what you can collect. Remember you must have permission to collect on private property.

See my page on Rockhounding Rules for general information on the rules of collecting rocks on various lands.