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William W. Jefferis

William Walter Jefferis was born in West Chester, Pennsylvania on January 12, 1820, and made his home in West Chester. He was educated in the West Chester Academy, and then took a position in the local bank while still in his teens. By 1857 he had worked his way up to the position of Cashier at the Bank of Chester County, second in command to the bank President, Dr. William Darlington. He held this position for the rest of his career, until 1883 when he retired for health reasons, and it must have paid quite well.

Jefferis had developed his first interest in minerals at the age of ten, and started collecting minerals seriously in 1837, probably while studying mineralogy at the Chester County Lyceum. For the next 60 years he worked tirelessly at enlarging it, until it came to be regarded as one of the finest private mineral collections in the country. It was rich in suites of minerals from eastern Pennsylvania and northern New York, many of the specimens self-collected. And he has one publication to his name: in 1864 he published Minerals of Chester County. Jefferis broadened his collection through exchanges and purchases from collectors and dealers in America and Europe, and accumulated countless specimens of calcite, barite and fluorite from classic British localities and significant suites from other European localities.

As a constant correspondent of important mineralogists of his day, including George Brush, James D. Dana and Benjamin Silliman, Jefferis often loaned specimens for study and illustration. Several of his specimens were illustrated in the 6th edition of Dana's System of Mineralogy--for example, phlogopite form Clark's Hill, St. Lawrence County, New York and clinochlore from West-town, Chester County, Pennsylvania. The mineral jefferisite was named in his honor by Prof. Brush, but later proved to be vermiculite and consequently the name was discredited. From 1877 to 1878 he served as Professor of Mineralogy at the West Chester Normal School, in addition to his duties at the bank. In 1883, after retiring from the bank, he moved to Philadelphia and took the position of curator to the William S. Vaux collection, a position he held for 15 years until 1898.

In 1900 the word got out that Jefferis was thinking of selling his enormous collection, and numerous important collectors and museums made a play for it. In 1904 Andrew Carnegie purchased Jefferis' entire collection, over 14,000 specimens, for $20,000 and in January of 1905 donated it to the Carnegie Museum of Natural History. Two railroad boxcars were needed to transport the collection to Pittsburgh. William, Jefferis died in New York on February 23, 1906.

JEFFERIS, A. E. (1911) A tribute to William Walter Jefferis. Reprinted in 1999 in Matrix, 7, (1), 21-26.
PENNYPACKER, C. H. (1895) Thw W. W. Jefferis collection. The Mineral Collector, 2, np.1 (March), p.4-5.
SOUZA, R. et al. (1990) The Hillman Hall of Minerals and Gems. Mineralogical Record, 21, no.5, special 32-page insert.
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[Citation format for this entry:
WILSON, Wendell E. (2019)
Mineralogical Record
Biographical Archive, at]
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The Mineralogical Record - William W. Jefferis Wiliam W. Jefferis
in 1860-1867
The Mineralogical Record - William W. Jefferis 41 x 63 mm,
A very early, handwritten Jefferis label for specimen no. 52, probably dating to the late 1830's.
The Mineralogical Record - William W. Jefferis 40 x 62 mm,
A very early, handwritten Jefferis lable for an unumbered specimen, probably dating to the late 1830's.
The Mineralogical Record - William W. Jefferis Very early Jefferis label, dated August 25, 1840, by which time his collection had already reached 764 specimens. 44 x 57 mm
The Mineralogical Record - William W. Jefferis 43 x 66 mm,
Early handwritten Jefferis label dated November 1, 1854 (no. 2031).
The Mineralogical Record - William W. Jefferis 45 x 68 mm,
Printed Jefferis lable dated 1859 (no. 2562).
The Mineralogical Record - William W. Jefferis 45 x 66 mm,
Label from the 1860's.
The Mineralogical Record - William W. Jefferis 46 x 67 mm,
Label dated October 16, 1867 (no. 4959).
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