Bringing the Fossils to Life Once the crates arrive at the Museum and the fossils are sorted into cabinets, they need to be prepared before they can be studied or put on display. A team of preparators works full-time to reveal the complete fossils from their stone tombs. Working under microscopes, fossil preparators use a variety of tools to carefully remove the matrix from the fossil, including dental picks, needles, and miniature air-powered jackhammers. Another tool that is useful, particularly with Green River Formation specimens (because the rock is relatively soft compared to the hard fossilized bone), is the air-abrasive machine, which is essentially a pinpoint sand-blaster. This tool shoots a very fine stream of powder that slowly eats the matrix away and leaves the fossil exposed and in tact. During your next visit to The Field Museum, be sure to stop by the McDonald's Prep Lab and watch the preparators at work.