The facts that the important mineral collection of Adam Seybert was purchased during the Academy's first year of existance and that its first president was also America's first crystallographer, stimulated interest in mineralogy, making that department one of the first and most active in the Academy. The collection has since grown into one of the best in the world, containing over 90% of all known minerals, and the museum display is rated one of the most effective in the country. This eminence has been achieved through 150 years of collecting expeditions, gifts and purchases.

While hundreds of names appear in the records, the major donations have come through Samuel Ashmead, Emily Drown, Thomas Harvey, Isaac Lea, William Maclure, Thomas M'Euen, Henry Seybert, Charles K. Shaw, William S. Vaux and Thomas B. Wilson. On deposit at the Academy are the collections of the American Philosophical Society, the Franklin Institute and the Commonwealth of Pennsylvania. Until the acquisition of the Vaux collection, in 1882, curatorial work was voluntary. Since that time the curators have been: Jacob Binder, William W. Jefferis, Theodore Rand, Frank J. Keeley and Samuel G. Gordon.

Included are catalogues, data on collections, memoranda and correspondence.