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The displays and research collections of minerals include many from famous localities in Delaware County, the United States and the World.

Some minerals have been named for members of the Delaware County Institute of Science, including John Cassin (Orthoclase Variety Cassinite) and first described from Pennsylvania (Lansfordite and Eastonite).

John Cassin was born in Upper Providence, Delaware County, PA, on September 6, 1813. Educated as a Quaker at Westtown School, he went on to become a world renowned ornithologist, naturalist, curator and Civil War veteran. Cassin was one of the five founding members of the Institute and signed the constitution on September 21, 1833.


In 1866 Isaac Lea described what at the time was thought to be a new mineral and named it after Cassin. It was later found to be a variety of Orthoclase and not a new mineral. Cassin died of arsenic poisoning on January 10, 1869 as the result of years of handling numerous birds preserved with arsenic. On display is a sample of Orthoclase Variety Cassinite from Blue Hill, Upper Providence Township, Delaware County, PA, collected by John Hinkson Smedley in the 1880’s.

One cabinet houses fluorescent minerals from Franklin, New Jersey. Displayed under UV short and UV long light, the minerals show their colors.

The Dr. George Smith collection comprises part of the minerals donated to the Institute. On November 22, 1834, Dr. Smith donated his collection of 170 minerals, mostly from the east coast of North America. He continued to donate specimens for many years to help build the Institute’s collection.

The museum also houses the original plate blocks used to print Samuel Gordon’s 1922 Mineralogy of Pennsylvania.

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