Ha, In am sure that you can find the lesws common things that starts with a J.
Not jewelry.
Rather, Jacuzzy, Jar filled with Jelly, Jigsaw puzzle, Juke box, Aircraft Joystick. Junky. Jury. Junk or Junk food. Jumbo Jet!

Oh! A nd how can I forget Jetty!

Just trying to spare you some time as you are a busy man.