Wollastonite rock
Wollastonite, also known as calcium metasilicate and composed of calcium, silicon, and oxygen, was named after the British scientist William Hyde Wollaston who lived in the late 18th and early 19th centuries. It’s a versatile mineral with diverse applications. In ceramics, wollastonite improves green strength and reduces crazing thanks to its unique acicular or needle-like crystal structure. It can be found in ceramic glazes and bodies, enamels, frits, and fluxes, and it reduces warping and cracking during firing.
Industrially, wollastonite has only been a major raw material for a few decades. Wollastonite production started in the U.S. in California, where only a few metric tons were mined per year, primarily for use as decorative stone. Since the late 1970s, however, this material has expanded into several industries and has been used as a replacement for asbestos in products like insulation, roofing tiles, paints, and fire-resistant construction materials. Wollastonite provides crack resistance, reinforcement, and high brightness in textured coatings like stucco, and all grades of wollastonite are used in the production of plastics. Wollastonite is an important ingredient in the production of steel and also in the manufacturing of friction devices such as brakes.
Vanderbilt Minerals mines wollastonite in northern Lewis County in New York state, and it is currently the only company producing the material in the U.S. NYCO Minerals, the only other company that mined wollastonite in this area, has ceased mining after selling its operations to the multinational conglomerate Imerys. In 2013, a statewide vote allowed NYCO to mine two-hundred acres of the Jay Mountain Wilderness. The proposal was supposed to save local jobs, but since Imerys’ acquisition of NYCO, the project hasn’t moved forward and former NYCO miners have expressed frustration towards Imerys.
Northern New York state is historically the territory of the Haudenosaunee, otherwise known as the Iroquois Confederacy, and Vanderbilt’s mines are located in what was likely the territory of the Oneida or Mohawk tribes.
Geologically, wollastonite occurs when limestones come into metamorphic contact within igneous rocks that are contaminated by carbon-rich intrusions. It can also occur when impure limestone or dolomite is subjected to high heat and pressure. Besides a billion-year-old history of continental collision and rifting, Northern New York state is characterized by the Adirondack Mountains, which are the result of a twenty-million-year-old dome of earth rising up at roughly a foot per year. Scientists have only just begun to understand this phenomenon. The wollastonite available in this region is likely related to this strange geologic activity.
Vanderbilt mines their wollastonite off New York Highway 3 between Harrisville and Natural Bridge, approximately 1 mile south of Lake Bonaparte. From there, it is trucked north to their warehouse where it is processed into their copyrighted product VANSIL W-30. The material is then trucked cross-country to Rocky Mountain Clay in Denver, and finally ends up at Colorado State University. This material travels a total of 1,955 miles from mine to studio.
The Adirondack Mountains
(where Wollastonite is mined)
