This presentation explores the geology and mineralogy of the Watchung Mountains of New Jersey, including the paragenesis of minerals formed within the region’s historic trap rock quarries. Topics will cover the history of New Jersey trap rock quarrying—past and present, the chemistry and formation of zeolite minerals, and how physical and molecular processes influence zeolite crystal development. Attendees will also learn about blasting operations at Prospect Park, notable trap rock mineral collectors, and the wide variety of minerals discovered in New Jersey trap rock quarries, highlighted by examples of some of the finest specimens ever recovered from these classic localities.