The Tilly Foster Mine Specimens
from the Harvard Mineralogical Museum
In 1810, a rich magnetite iron deposit was discovered in Brewster, Putnam County on farmland later owned by Tillingham (Tilly) Foster. Large-scale mining began in 1853, and by 1879, the mine reached a depth of 600 feet. The mine produced a total of about 700,000 tons of ore and at its peak employed approximately 300 miners. The Tilly Foster mine closed shortly after a tragic rockslide in 1897 killed 13 miners.
hmm121906hmm121066 The ore body was enclosed in a gneiss, a common rock in the Hudson Highlands. Outstanding specimens of magnetite, chondrodite, clinochlore, brucite, serpentine and titanite are just a few of the more than 90 mineral species collected at the mine.

Elwood P. Hancock (1834-1916), an active collector of New York and New Jersey minerals, purchased specimens directly from the miners in the late 19th century. His collection was acquired by The Mineralogical Museum of Harvard University in 1916 and is currently on loan to the New York State Museum.

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