I do not have access to real-time data, and the thickness of Pennsylvania Black Slate slabs can vary. However, according to various sources, the typical thickness of Pennsylvania Black Slate slabs can range from 1/4 inch to 1 inch, depending on the application and installation method. Some slabs can be thicker, up to 2 inches or more, for specific purposes such as wall cladding or flooring in high-foot-traffic areas. Its best to consult with a reputable supplier or installer to determine the appropriate thickness for your project.