Founded in 1831 as the Elkinton Company and later renamed, Philadelphia Quartz Company became an important innovator during World War I by discovering that silica gels could be used as a base to manufacture catalysts for cracking crude oil molecules to make high-octane gasoline and developing potassium silicate which was adopted for use in cathode ray tubes.

The history of the Philadelphia Quartz Company has been inextricably linked to that of its founding family, the Elkintons, for most of its 154-year existence. George Elkinton (1650-1713), a Quaker blacksmith from Oxfordshire, England, immigrated to the United States in 1677 as an indentured servant. After serving out his time, he was given a small land grant in Burlington, New Jersey, where he settled, raised a family, and attempted to earn a living as a farmer.

George Elkinton died in 1713, and his son Joseph Elkinton (1690-1724) inherited the family land. Five years later however, he was forced to sell it, and the Elkintons once again began earning their living as artisans. The family remained in southern New Jersey for seventy-five years until George Elkinton's great-grandson, Asa Elkinton (1765-1824), his wife Letitia Lippincott Elkinton (1766-1806), and their four children moved to Philadelphia.

For more than fifteen years, Asa Elkinton struggled to earn a living as a tailor. Finally, in 1810, he was forced to abandon his trade, and he opened a grocery store on Front Street. When this business did not succeed, he set up a small shop to manufacture candles and soaps. George M. Elkinton (1798-1878), the Elkinton's youngest son, joined his father as a partner in the family business. Joseph Elkinton (1794-1850), the eldest, apprenticed as a silversmith. When he finished his training in 1816, he moved to Tunessassa, New York, where he spent the next fifteen years of his life working for the society of Friends as a missionary. Joseph returned to Philadelphia in 1831. By this time, Asa had died and George had taken over the business. Joseph set up another candle and soap shop at 377 South Second street.

While George's business stagnated, Joseph's immediately prospered. By the end of the 1830s, his trade had expanded far beyond the Philadelphia area. Sales records document shipments to New York, New Orleans, Pittsburgh, and North Carolina. Though it produced only soaps and candles, the Elkinton firm dealt in a wide variety of commodities. Early day-books record barter transactions in coffee, cordwood, coal, flour, hay, butter, salt, and bricks. By 1842, Joseph Elkinton had accumulated enough capital to build a three-story brick factory. Shortly thereafter, he brought his sons, Joseph S. Elkinton (1830-1905) and Thomas Elkinton (1836-1901), into the business.

Thomas Elkinton was an amateur chemist with an inquiring and innovative mind. At first, he applied his talents to developing a diversified product line of "fancy and specialty soaps." After these were successfully marketed, he turned his attention to the development of a synthetic detergent. By reading German chemical journals, he became acquainted with European efforts to synthesize soluble silicates. In the 1840s, German scientists had discovered that these silicates, which were produced by the fusion of sand and soda ash, had a variety of potential industrial applications. he hypothesized that they could be used as a possible substitute for rosin, the key detergent agent in soap. In 1857, he built a furnace capable of manufacturing large quantities of soluble silicates. After a series of experiments, the Elkinton firm began producing soaps with a silicate base. The timing could not have been more fortuitous. During the civil War, supplies of rosin from the South were cut off, leaving Northern soap makers without an essential raw material. The Elkinton firm thus found a huge market for its synthetic soap.

By 1862, when Joseph Elkinton retired and his sons took over the business, the firm was marketing soluble silicates throughout much of the Northeast and Middle West.

To meet this increasing demand, the company constructed a second factory at Ninth and Mifflin Streets. This facility was built in partnership with John Greacen (dates unknown) and Samuel Booth (dates unknown), who provided the necessary capital.

The Ninth and Mifflin factory was called the Philadelphia Quartz Company, since it was devoted to the manufacture of soluble silicates. In 1868, the Elkintons bought out Greacen and Booth, and the firm came under family control.

The Philadelphia Quartz Company steadily expanded. By the late 1870s, it was marketing sixteen grades of silicates. In 1875, the Elkintons hired Charles W. Goudy (1818-1903) as their first sales agent. Goudy was extremely effective. During this twenty years with the company, sales of soluble silicates increased from 8.7 to 14.8 million pounds per year. Thomas Elkinton continued his laboratory work, exploring a variety of new uses for industrial silicates. By the last decade of the nineteenth century, the Elkintons were selling their product to manufacturers of lye, fertilizers, detergents, oils, greases, adhesives, fiber, and wall board. During this period, the company built seven plants outside Philadelphia. The Anderson, Indiana, factory was constructed in 1889 and represented the company's first attempt to locate a plant near an important market. In 1904, after a third generation of Elkintons; William T. Elkinton (1860-1933) and Alfred C. Elkinton (1863-1940), had assumed control, the company abandoned the soap business in order to focus all its resources on the industrial market.

World War I created an array of opportunities and opened up new markets for soluble silicates. Dr. James Vail (1886-1951), who came to the company as a young chemist in 1905, played a key role in its research and development effort. In 1918, as head of the Chemical Department, Vail discovered that silica gels, made from sodium silicate, could be used as a base for the catalysts that were needed to crack crude oil molecules to make high-octane gasoline. Vail also developed a potassium silicate that was soon adapted for use in cathode ray tubes. This innovation had important implications for the emerging television and radar industries. However, the Philadelphia Quartz Company was a small firm and faced competition from the E.I. du Pont de Nemours and Allied Chemical Companies. Although it managed to carve out a portion of the market for itself and continued to retain a reputation of a technological innovator, it could not hope to compete with the larger firms in the industry.

Nevertheless, Philadelphia Quartz continued to grow during the World War II and immediate post-War periods. By the 1960s, however, it became clear that as a traditional family firm the company had grown increasingly conservative and was unable to take advantage of all its potential market opportunities. A restructuring led to a rational integration of the sales and marketing departments. Also, as part of this new approach, affiliates and subsidiaries were fully merged into the parent company. In the summer of 1973, Philadelphia Quartz Company moved out of Philadelphia in order to occupy a new facility in Valley Forge. Its name was officially changed to PQ Corporation in 1978.