THE MODERN PERIOD:
During the period from the end of the First World War to the beginning of World War II, mining in New York State generally declined. Graphite mining ceased. Quarries for building stone greatly diminished. Only a few of the largest iron mines survived and but two garnet mines remained in operation during the early part of this period. Two small emery (abrasive) mines in Westchester County eventually failed. However, the Second World War brought resurgence in some quarters of the mining industry. Because of the necessity of a domestic source for certain raw materials, large iron mines in the Adirondack counties of Essex, Clinton and St. Lawrence were rejuvenated. From 1938 to 1945, more than eight million tons of ore were produced from the mines at Mineville, Essex County, alone. A nineteenth century iron mine at Tahawus in Essex County was reincarnated as an ilmenite (FeTiO3) mine to provide titanium dioxide, an essential component of paint pigment and chemical smoke screens. These mines remained in operation for as much as forty years but all were closed by 1982 and neither iron nor titanium were being mined in New York State by the beginning of the twenty-first century. The last of the gypsum mines closed in 1999.
Some mines did fare well in the modern period. Industrial talc mines in St. Lawrence County expanded. The talc was used for filler in paper, ceramics and rubber. It was not used for cosmetics. The talc mines closed in 2008. Mines for sphalerite (ZnS), a primary zinc ore, were established in 1920 and continued to operate in St. Lawrence County until 2008. Halite, extracted both as rock salt and brine is still an important commodity. Clay for landfill cover and portland cement is mined. Small mines produce peat for agricultural purposes. Garnet is still produced for abrasives and water filtration. During this modern period, a new commodity came to maturity. The mineral wollastonite (CaSi03) entered the market as a filler material and found particular utility in the manufacture of molded resin automobile body panels. Two New York State mines in the Adirondacks produce a third of the world’s supply of this mineral. Granite, slate and bluestone (sandstone) quarries show continued strength. By far the most important mines in the state of New York in the modern period are those that produce construction aggregates (crushed stone, sand and gravel) and portland cement.
At the beginning of the twenty-first century, there were 2,500 operating mines in New York State. These mines provided direct employment for about 5,000 people and indirect employment, that is jobs for people who use the products, for five times that number. Ninety percent of the mines are for construction aggregates which are used to build road, houses, schools, airports and many other projects that use fill, concrete or asphalt. New York was the only state to produce wollastonite, and was first in production of garnet, third in salt, sixth in dimension stone, and eighth in portland cement. The following table lists mineral production in New York State in recent years.