The Bryn Mawr College Rock & Mineral Collection houses more than 100,000 specimens of rocks, minerals, gems, thin sections, and geologic research specimens — including classic mineral beauties, mineral oddities like petrified lightning, and a deep sampling of rocks and minerals from the Philadelphia region. 

Selected specimens are on display in the Bryn Mawr College Park Science Center, which is free and open to the public during regular business hours.