William W. Jefferis

January 12, 1820 - February 23, 1906

Born in West Chester, Pennsylvania in 1820, William W. Jefferis began collecting minerals in 1837. He began his career in banking in his home town while still in his teens and by 1857 had worked his way through the ranks to become second in command to the Bank of Chester County’s President. He held this position through his entire professional career while devoting his considerable academic interest to the collection of mineral specimens, even serving one year as Professor of Mineralogy at the West Chester Normal School while still holding his banking position.

Most of his mineral specimens originated from eastern Pennsylvania, New York, and the British Isles. His collection was predominantly self-collected, but he did trade and purchase minerals from other collectors in America and Europe, and his collection became very well-known. He often lent his specimens for academic study and illustration. He wrote one book, Minerals of Chester County, published in 1864.

He retired from the bank in 1883 and became curator of the William S. Vaux collection, a position he held for 15 years. In 1900, word began to circulate that he was interested in selling his considerable collection and in 1904 it was Andrew Carnegie who sealed the deal for $20,000. In 1905, Carnegie donated it to the Carnegie Museum of Natural History. Two railroad boxcars were needed to transport it from Jefferis’ home in Philadelphia to Pittsburgh, where it became the foundation for the museum’s mineral collection.