Collectors: William W. JefferisJEFFERISPHOTO

The William W. Jefferis (1820–1906) Mineral Collection of more than 14,000 specimens was purchased by Andrew Carnegie in 1904 for $20,000. It formed the foundation of the museum’s mineral collection. Among Jefferis’ collection were excellent specimens from eastern Pennsylvania, northern New York, and the British Isles. The collection contained many specimens of fluorite, calcite, and barite. Every specimen in the Tin Isles locality suite on display in Hillman Hall of Minerals and Gems is from the Jefferis Mineral Collection.

Jefferis began collecting minerals in 1837 and expanded his collection for 60 years. He worked as a very successful banker for most of his life, and after retiring he served as curator of the William S. Vaux Collection for fifteen years. He was also a Professor of Mineralogy at the West Chester Normal School for one year. Throughout his life, he published only one book: Minerals of Chester County (1864). However, his collection was very well known and he often lent out specimens for study and illustration.


Calcite from England
Photo: Harold and Erica Van Pelt