Guitar pickups are made from several different materials. The most common are magnets, wire, and some form of insulation to prevent the pickups from shorting out. The main components in a pickup are the magnets and coil. Besides that, they are made from either Alnico (Aluminum/Nickel/Cobalt) or Ceramic. The coil is copper wire wrapped around a bobbin (like a transformer). The insulation is generally epoxy but can also be wax or varnish.