In the 1820s, a chemist by the name of Isaac Tyson Jr. made a serendipitous discovery that would change the course of industrial history. At a busy market in Baltimore, Tyson watched a man drive a cart holding a barrel that was propped on some peculiar rocks. Tyson, who already operated a modest chromite mine near Baltimore, recognized the material as chromite. Tyson supposedly followed the man north where he found chromite deposits in Lancaster County.
Regardless of how he made his discovery, Tyson knew one key bit of information that led to his astounding success. He realized that chromite, the mineral form of the element chrome, occurs in deposits of serpentine, a rare green rock that is abundant in Chester County. Once processed, the heavy black material becomes a key ingredient in the production of “chrome yellow” pigments and dyes.
Tyson quickly acquired land, 32 properties in Chester County alone, and began mining the material. His chromite empire covered portions of Lancaster County, Chester County and northern Maryland. His workforce consisted of Irishmen and local farmers who found mining more profitable than farming.
Tyson shipped the extracted chromite to Philadelphia to create paint pigments and to Liverpool, England, to produce dyes. Tyson’s mines, the first chromite mines in the U.S., were a virtual monopoly until about 1850. Until that time, he supplied nearly all of the chrome used in the entire world.
As explained by Heather Hansen, collections manager at the Chester County Historical Society, the mineral dye “chrome yellow was brighter, more opaque and resembled a more ‘acid’ color than previously used organic dyes.” The demand was high, as “chrome yellow was very popular on printed cottons in the 1840s and replaced natural yellow dyes.”
By the middle of the 19th century, the mines became exhausted and chromite discoveries in Turkey broke Tyson’s string of success. Tyson passed away in 1861. However, his family business continued in Maryland for decades until the Mutual Chemical Co. of America purchased it in 1908. Chrome processing continued at his Fells Point, Baltimore, site under the direction of Allied Chemical Corp. until the 1980s.
Jane L. S. Davidson, the former Chester County heritage preservation coordinator who passed away earlier this year, extensively researched Tyson’s chromite empire. “He became known as the ‘Chrome King of the World,’” Davidson noted during an interview in 2005. In 1996, Tyson was even inducted into the National Mining Hall of Fame in Leadville, Colorado. According to the Hall of Fame, “Tyson fathered the American chromium industry” and pioneered many other chemical processes.
Today, chrome is well-known as the stainless part of stainless steel. But according to one legend, it played a big part in the development of a recognizable transportation icon – the yellow taxi cab. Englishman Andreas Kurtz’s experiments with chrome colors during the 1830s led to the painting of Princess Charlotte’s carriage a bright chrome yellow. Yellow-hued carriages became fashionable with other nobility, thus supposedly starting the trend of yellow cabs.
Chromite is just part of a much larger story of mining and minerals in Chester County. Ronald A. Sloto’s book the “Mines and Minerals of Chester County Pennsylvania” states that the county “has a rich mining and mineral history that spans more than two centuries.” However, “all but a few quarries and mines have closed, and many mineral localities have disappeared as the landscape has evolved from agricultural to suburban.” As noted by Architectural Historian Jane Dorchester, the recognizable green-hued serpentine in the southern portions of Chester County was rarely used for building purposes, unlike stone from quarries found further north in the county.
Jay M. Gregg, CPRP, regional park superintendent with Chester County Facilities & Parks, notes that the mineral history of the region did not end with the chromite activity in the 19th century. “When World War I increased demands for metals and also threatened access to overseas reserves,” Gregg describes today, “efforts were undertaken to extract chromite from the barrens through placer mining.” This type of mining used water to extract chromite from stream sediments. Although a mill was created to process the metal, according to Gregg, the “mill never achieved commercial viability, and was soon abandoned when global chromite supplies stabilized.”
At Nottingham County Park, which includes a portion of the chromite mines of Tyson’s empire, you can explore the area’s natural and industrial history. The park’s land, which the county purchased for $28,000 in 1962, was dedicated in September 1963. In 2009, the U.S. Department of the Interior named the park’s Serpentine Barrens a National Natural Landmark in recognition of their uniqueness and significance. The park will hold a 50th anniversary celebration this fall.
--Rob Lukens is president of the Chester County Historical Society. For information visit www.chestercohistorical.org.