Yes, magnetic fields will certainly pass through glass. You can even perform a simple experiment to verify this: take two permanent magnets, place them on either side of a glass jar, and feel how they attract to each other. That attraction indicates that the magnetic field is propagating through the glass. If the magnets are strong enough, the magnets will even attract each other through your own hand! In fact, magnetic fields will pass through most ordinary materials, like wood, concrete, Teflon, copper, or water. All materials can be classified by how they will interact with magnetic fields: (1) diamagnetic materials will create an induced magnetic field that opposes the applied magnetic field, (2) paramagnetic materials will create an induced magnetic field that will attract toward the source of the applied magnetic field, and (3) ferromagnetic materials are the strong permanent magnets that we encounter in everyday life.

The strength of an applied magnetic field as it propagates through a material will depend on the strength of the applied magnetic field, the specific type of intervening material, and the thickness of the material. Superconductors—such as lead, tin, and mercury—are the special class of materials that will not allow any magnetic field to pass through it. Superconductors can be used to levitate other magnets, which allow engineers to build high-speed magnetic levitating trains.